Highly pure halogenated rubbers

ABSTRACT

The invention relates to a method to reduce or prevent agglomeration of particles of halogenated rubbers in aqueous media by LCST compounds as well as highly pure halogenated rubbers. The invention further relates to halogenated elastomer products comprising the same or derived therefrom.

FIELD OF THE INVENTION

The invention relates to a method to reduce or prevent agglomeration ofparticles of halogenated rubbers in aqueous media by LCST compounds aswell as highly pure halogenated rubbers. The invention further relatesto halogenated elastomer products comprising the same or derivedtherefrom.

BACKGROUND

Halogenated rubbers in particular those comprising repeating unitsderived from isoolefins are industrially prepared by carbocationicpolymerization processes. Of particular importance are chlorobutylrubber and bromobutyl rubber which are halogenated elastomers ofisobutylene and a smaller amount of a multiolefin such as isoprene.

In the conventional process for producing halogenated butyl rubber (alsodenoted as halobutyl rubber or HIIR) e.g. isobutene and isoprene arefirst polymerized in a polar halohydrocarbon medium, such as methylchloride with an aluminum based initiating system, typically eitheraluminum trichloride (AlCl₃) or ethyl aluminum dichloride (EtAlCl₂). Thebutyl rubber does not appreciably dissolve in this polar medium, but ispresent as suspended particles and so this process is normally referredto as a slurry process. Residual monomers and polymerization medium arethen steam stripped from the butyl rubber, before it is dissolved in anorganic medium, typically a non-polar medium such as hexane. Thehalogenation process ultimately produces the final halogenated productin a conventional manner.

After halogenation of butyl rubber the reaction mixture typicallycomprises the butyl halogenated rubber and the diluent. This mixturewhich is typically a solution is after neutralization and phaseseparation typically either batchwise or more commonly in industrycontinually transferred into a steam-stripper wherein the aquous phasecomprises an anti-agglomerant which for all existing commercial gradestoday is a fatty acid salt of a multivalent metal ion, in particulareither calcium stearate or zinc stearate in order to form and preservehalogenated butyl rubber particles, which are more often referred to as“halobutyl rubber crumb”

The water in this vessel is typically steam heated to remove and recoverthe diluent.

As a result thereof a slurry of halogenated butyl rubber particles isobtained which is then subjected to dewatering to isolate halogenatedbutyl rubber particles. The isolated halogenated butyl rubber particlesare then dried, baled and packed for delivery.

The anti-agglomerant ensures that in the process steps described abovethe halogenated butyl rubber particles stay suspended and show a reducedtendency to agglomerate.

In the absence of an anti-agglomerant the naturally high adhesion ofhalogenated butyl rubber would lead to rapid formation of anon-dispersed mass of rubber in the process water, plugging the process.In addition to particle formation, sufficient anti-agglomerant must beadded to delay the natural tendancy of the formed halogenated butylrubber particles to agglomerate during the stripping process, whichleads to fouling and plugging of the process.

The anti-agglomerants in particular calcium and zinc stearates functionas a physical-mechanical barrier to limit the close contact and adhesionof butyl rubber particles.

The physical properties required of these anti-agglomerants are a verylow solubility in water which is typically below 20 mg per liter understandard conditions, sufficient mechanical stability to maintain aneffective barrier, and the ability to be later processed and mixed withthe butyl rubber to allow finishing and drying.

The fundamental disadvantage of fatty acid salts of a mono- ormultivalent metal ion, in particular sodium, potassium calcium or zincstearate or palmitate is their chemical interaction with rubber curesystems.

Therefore, there is still a need for providing a process for thepreparation of halogenated rubber particles in aqueous media havingreduced or low tendency of agglomeration.

SUMMARY OF THE INVENTION

According to one aspect of the invention, there is provided a processfor the preparation of an aqueous slurry comprising a plurality ofelastomer particles suspended therein, the process comprising at leastthe step of:

-   -   A) contacting an organic medium comprising        -   i) at least one halogenated elastomer and        -   ii) an organic diluent with an aqueous medium comprising at            least one LCST compound having a cloud point of 0 to 100°            C., preferably 5 to 100° C., more preferably 15 to 80° C.            and even more preferably 20 to 70° C. and    -   B) removing at least partially the organic diluent to obtain the        aqueous slurry comprising the halogenated elastomer particles.

DETAILED DESCRIPTION OF THE INVENTION

The invention also encompasses all combinations of preferredembodiments, ranges parameters as disclosed hereinafter with either eachother or the broadest disclosed range or parameter.

The term halogenated elastomers include any halogenated polymer showingelastomeric behaviour. Examples of such polymers include but are notlimited to halogenated butyl rubbers, and halogenated terpolymers.

In one embodiment the organic medium comprising at least one halogenatedelastomer and an organic diluent is obtained from a halogenation,optionally after neutralization and/or phase separation steps.

The aqueous medium may further contain non-LCST compounds selected fromthe group consisting of ionic or non-ionic surfactants, emulsifiers, andantiagglomerants in particular salts of mono- or multivaltent metal ionssuch as stearates or palmitates in particular those of sodium,potassium, calcium and zinc.

In one embodiment the aqueous medium therefore comprises 20.000 ppm orless, preferably 10.000 ppm or less, more preferably 8.000 ppm or less,even more preferably 5.000 ppm or less and yet even more preferably2.000 ppm or less and in another yet even more preferred embodiment1.000 ppm or less of non-LCST compounds whereby the non-LCST compoundsare

-   -   selected from the group consisting of ionic or non-ionic        surfactants, emulsifiers, and antiagglomerants or are in another        embodiment    -   salts of (mono- or multivalent) metal ions or are in another        embodiment    -   carboxylic acid salts of multivalent metal ions or are in        another embodiment    -   stearates or palmitates of mono- or multivalent metal ions or        are in another embodiment    -   calcium and zinc stearates or palmitates.

In one embodiment, the abovementioned amounts are with respect to theamount of elastomer present in the organic medium.

In another embodiment the aqueous medium comprises 500 ppm or less,preferably 100 ppm or less, more preferably 50 ppm or less, even morepreferably 30 ppm or less and yet even more preferably 10 ppm or lessand in another yet even more preferred embodiment 1.000 ppm or less ofnon-LCST compounds whereby the non-LCST compounds are

-   -   selected from the group consisting of ionic or non-ionic        surfactants, emulsifiers, and antiagglomerants or are in another        embodiment    -   salts of (mono- or multivalent) metal ions or are in another        embodiment    -   carboxylic acid salts of multivalent metal ions or are in        another embodiment    -   stearates or palmitates of mono- or multivalent metal ions or        are in another embodiment    -   calcium and zinc stearates or palmitates.

In one embodiment, the abovementioned amounts are with respect to theamount of elastomer present in the organic medium).

If not expressly stated otherwise ppm refers to parts per million byweight.

In one embodiment the aqueous medium comprises of from 0 to 5,000 ppm,preferably of from 0 to 2,000 ppm, more preferably of from 10 to 1,000ppm, even more preferably of from 50 to 800 ppm and yet even morepreferably of from 100 to 600 ppm of salts of mono or multivalent metalions calculated on their metal content and with respect to the amount ofhalogenated elastomer present in the organic medium.

In another embodiment the aqueous medium comprises of from 0 to 5,000ppm, preferably of from 0 to 2,000 ppm, more preferably of from 10 to1,000 ppm, even more preferably of from 50 to 800 ppm and yet even morepreferably of from 100 to 600 ppm of salts of multivalent metal ionscalculated on their metal content and with respect to the amount ofhalogenated elastomer present in the organic medium.

In another embodiment the weight ratio of salts of stearates, palmitatesand oleates of mono- and multivalent metal ions, if present, to the LCSTcompounds is of from 1:2 to 1:100, preferably 1:2 to 1:10 and morepreferably of from 1:5 to 1:10 in the aqueous medium.

In one embodiment the aqueous medium comprises 550 ppm or less,preferably 400 ppm or less, more preferably 300 ppm or less, even morepreferably 250 ppm or less and yet even more preferably 150 ppm or lessand in another yet even more preferred embodiment 100 ppm or less ofsalts of metal ions calculated on their metal content and with respectto the amount of halogenated elastomer present in the organic medium.

In yet another embodiment the aqueous medium comprises 550 ppm or less,preferably 400 ppm or less, more preferably 300 ppm or less, even morepreferably 250 ppm or less and yet even more preferably 150 ppm or lessand in another yet even more preferred embodiment 100 ppm or less ofsalts of multivalent metal ions calculated on their metal content andwith respect to the amount of halogenated elastomer present in theorganic medium.

In one embodiment, the aqueous medium comprises 8.000 ppm or less,preferably 5.000 ppm or less, more preferably 2.000 ppm or less, yeteven more preferably 1.000 ppm or less, in another embodiment preferably500 ppm or less, more preferably 100 ppm or less and even morepreferably 15 ppm or less and yet even more preferably no or from 1 ppmto 10 ppm of non-ionic surfactants being non-LCST compounds selectedfrom the group consisting of ionic or non-ionic surfactants,emulsifiers, and antiagglomerants and with respect to the amount ofhalogenated elastomer present in the organic medium.

As used herein a LCST compound is a compound which is soluble in aliquid medium at a lower temperature but precipitates from the liquidmedium above a certain temperature, the so called lower criticalsolution temperature or LCST temperature. This process is reversible, sothe system becomes homogeneous again on cooling down. The temperature atwhich the solution clarifies on cooling down is known as the cloud point(see German standard specification DIN EN 1890 of September 2006). Thistemperature is characteristic for a particular substance and aparticular method.

Depending on the nature of the LCST compound which typically compriseshydrophilic and hydrophobic groups the determination of the cloud pointmay require different conditions as set forth in DIN EN 1890 ofSeptember 2006. Even though this DIN was originally developed fornon-ionic surface active agents obtained by condensation of ethyleneoxide this method allows determination of cloud points for a broadvariety of LCST compounds as well. However, adapted conditions werefound helpful to more easily determine cloud points for structurallydifferent compounds.

Therefore the term LCST compound as used herein covers all compoundswhere a cloud point of 0 to 100° C., preferably 5 to 100° C., morepreferably 15 to 80° C. and even more preferably 20 to 80° C. can bedetermined by at least one of the following methods:

-   -   1) DIN EN 1890 of September 2006, method A    -   2) DIN EN 1890 of September 2006, method C    -   3) DIN EN 1890 of September 2006, method E    -   4) DIN EN 1890 of September 2006, method A wherein the amount of        compound tested is reduced from 1 g per 100 ml of distilled        water to 0.05 g per 100 ml of distilled water.    -   5) DIN EN 1890 of September 2006, method A wherein the amount of        compound tested is reduced from 1 g per 100 ml of distilled        water to 0.2 g per 100 ml of distilled water.

In another embodiment the cloud points indicated above can be determinedby at least one of the methods 1), 2) or 4).

In a preferred embodiment the LCST compounds are those which cloudpoints can be determined by at least on of the methods 1), 3) or 4).

As a consequence, non-LCST compounds are in general those compoundshaving either no cloud point or a cloud point outside the scope asdefined hereinabove. It is apparent to those skilled in the art andknown from various commercially available products, that the differentmethods described above may lead to slightly different cloud points.However, the measurements for each method are consistent andreproducible within their inherent limits of error and the generalprinciple of the invention is not affected by different LCSTtemperatures determined for the same compound as long as with at leastone of the above methods the cloud point is found to be within theranges set forth above.

For the sake of clarity it should be mentioned that metal ions, inparticular multivalent metal ions such as aluminum already stemming fromthe initiator system employed in step b) are not encompassed by thecalculation of metal ions present in the aqueous medium employed in stepA).

In another embodiment, the aqueous medium comprises 70 ppm or less,preferably 50 ppm or less, more preferably 30 ppm or less and even morepreferably 20 ppm or less and yet even more preferably 10 ppm or less ofsalts of multivalent metal ions calculated on their metal content andwith respect to the amount of halogenated elastomer present in theorganic medium.

In yet another embodiment, the aqueous medium comprises 25 ppm or less,preferably 10 ppm or less, more preferably 8 ppm or less and even morepreferably 7 ppm or less and yet even more preferably 5 ppm or less ofsalts of multivalent metal ions calculated on their metal content andwith respect to the amount of halogenated elastomer present in theorganic medium.

In another embodiment, the aqueous medium comprises 550 ppm or less,preferably 400 ppm or less, more preferably 300 ppm or less, even morepreferably 250 ppm or less and yet even more preferably 150 ppm or lessand in another yet even more preferred embodiment 100 ppm or less ofcarboxylic acid salts of multivalent metal ions calculated on theirmetal content and with respect to the amount of halogenated elastomerpresent in the organic medium, whereby the carboxylic acids are selectedfrom those having 6 to 30 carbon atoms, preferably 8 to 24 carbon atoms,more preferably 12 to 18 carbon atoms. In one embodiment such carboxylicacids are selected from monocarboxylic acids. In another embodiment suchcarboxylic acids are selected from saturated monocarboxylic acids suchas stearic acid.

The following example shows how the calculation is performed.

The molecular weight of calcium stearate (C₃₆H₇₀CaO₄) is 607.04 g/mol.The atomic weight of calcium metal is 40.08 g/mol. In order to providee.g. 1 kg of an aqueous medium comprising 550 ppm of a salts of amultivalent metal ion (calcium stearate) calculated on its metal content(calcium) and with respect to the amount of halogenated elastomerpresent in the organic medium that is sufficient to form a slurry from aorganic medium comprising 10 g of a halogenated elastomer the aqueousmedium must comprise (607.04/40.08)×(550 ppm of 10 g)=83 mg of calciumstearate or 0.83 wt.-% with respect to the halogenated elastomer or 83ppm with respect to the aqueous medium. The weight ratio of aqeousmedium to halogenated elastomer present in the organic medium would inthis case be 100:1.

In yet another embodiment, the aqueous medium comprises 70 ppm or less,preferably 50 ppm or less, more preferably 30 ppm or less and even morepreferably 20 ppm or less and yet even more preferably 10 ppm or less ofcarboxylic acid salts of multivalent metal ions calculated on theirmetal content and with respect to the amount of halogenated elastomerpresent in the organic medium, whereby the carboxylic acids are selectedfrom those having 6 to 30 carbon atoms, preferably 8 to 24 carbon atoms,more preferably 12 to 18 carbon atoms. In one embodiment such carboxylicacids are selected from monocarboxylic acids. In another embodiment suchcarboxylic acids are selected from saturated monocarboxylic acids suchas palmitic acid or stearic acid.

In yet another embodiment, the aqueous medium comprises 25 ppm or less,preferably 10 ppm or less, more preferably 8 ppm or less and even morepreferably 7 ppm or less and yet even more preferably 5 ppm or less ofcarboxylic acid salts of multivalent metal ions calculated on theirmetal content and with respect to the amount of halogenated elastomerpresent in the organic medium, whereby the carboxylic acids are selectedfrom those having 6 to 30 carbon atoms, preferably 8 to 24 carbon atoms,more preferably 12 to 18 carbon atoms. In one embodiment such carboxylicacids are selected from monocarboxylic acids. In another embodiment suchcarboxylic acids are selected from saturated monocarboxylic acids suchas stearic acid.

In one embodiment the aqueous medium is free of carboxylic acid salts ofmultivalent metal ions whereby the carboxylic acids are selected fromthose having 6 to 30 carbon atoms, preferably 8 to 24 carbon atoms, morepreferably 12 to 18 carbon atoms. In one embodiment such carboxylicacids are selected from monocarboxylic acids. In another embodiment suchcarboxylic acids are selected from saturated monocarboxylic acids suchas stearic acid.

In another embodiment, the aqueous medium comprises 100 ppm or less,preferably 50 ppm or less, more preferably 20 ppm or less and even morepreferably 15 ppm or less and yet even more preferably 10 ppm or less ofsalts of monovalent metal ions calculated on their metal content andwith respect to the amount of halogenated elastomer present in theorganic medium.

In another embodiment, the aqueous medium comprises additionally oralternatively 100 ppm or less, preferably 50 ppm or less, morepreferably 30 ppm or less, even more preferably 20 ppm or less and yeteven more preferably 10 ppm or less and in another yet even morepreferred embodiment 5 ppm or less of carboxylic acid salts ofmonovalent metal ions such as sodium stearate, sodium palmitate andsodium oleate and potassium stearate, potassium palmitate and potassiumoleate calculated on their metal content and with respect to the amountof halogenated elastomer present in the organic medium, whereby thecarboxylic acids are selected from those having 6 to 30 carbon atoms,preferably 8 to 24 carbon atoms, more preferably 12 to 18 carbon atoms.In one embodiment such carboxylic acids are selected from monocarboxylicacids. In another embodiment such carboxylic acids are selected fromsaturated monocarboxylic acids such as stearic acid. Examples ofmonovalent salts of carboxylic acids include sodium stearate, palmitateand oleate as well as potassium stearate, palmitate and oleate.

In one embodiment the aqueous medium is free of carboxylic acid salts ofmonovalent metal ions whereby the carboxylic acids are selected fromthose having 6 to 30 carbon atoms, preferably 8 to 24 carbon atoms, morepreferably 12 to 18 carbon atoms. In one embodiment such carboxylicacids are selected from monocarboxylic acids. In another embodiment suchcarboxylic acids are selected from saturated monocarboxylic acids suchas palmitic or stearic acid.

In another embodiment the aqueous medium comprises of from 0 to 5,000ppm, preferably of from 0 to 2,000 ppm, more preferably of from 10 to1,000 ppm, even more preferably of from 50 to 800 ppm and yet even morepreferably of from 100 to 600 ppm of

-   -   carbonates of multivalent metal ions calculated on their metal        content and with respect to the amount of halogenated elastomer        present in the organic medium or in another embodiment of    -   magnesium carbonate and calcium carbonate calculated on their        metal content and with respect to the amount of halogenated        elastomer present in the organic medium.

In another embodiment, the aqueous medium comprises 550 ppm or less,preferably 400 ppm or less, more preferably 300 ppm or less, even morepreferably 250 ppm or less and yet even more preferably 150 ppm or lessand in another yet even more preferred embodiment 100 ppm or less of

-   -   carbonates of multivalent metal ions calculated on their metal        content and with respect to the amount of halogenated elastomer        present in the organic medium or in another embodiment of    -   magnesium carbonate and calcium carbonate calculated on their        metal content and with respect to the amount of halogenated        elastomer present in the organic medium.

In yet another embodiment, the aqueous medium comprises 70 ppm or less,preferably 50 ppm or less, more preferably 30 ppm or less and even morepreferably 20 ppm or less and yet even more preferably 10 ppm or less of

-   -   carbonates of multivalent metal ions calculated on their metal        content and with respect to the amount of copolymer present in        the organic medium obtained according to step b) or in another        embodiment of    -   magnesium carbonate and calcium carbonate calculated on their        metal content and with respect to the amount of halogenated        elastomer present in the organic medium.

The term multivalent metal ions encompasses in particular bivalent earthalkaline metal ions such as magnesium, calcium, strontium and barium,preferably magnesium and calcium, trivalent metal ions of group 13 suchas aluminium, multivalent metal ions of groups 3 to 12 in particular thebivalent metal ion of zinc.

The term monovalent metal ions encompasses in particular alkaline metalions such as lithium, sodium and potassium.

In another embodiment, the aqueous medium comprises 500 ppm or less,preferably 200 ppm or less, more preferably 100 ppm or less, even morepreferably 50 ppm or less and yet even more preferably 20 ppm or lessand in another yet even more preferred embodiment no layered mineralssuch as talcum calculated with respect to the amount of halogenatedelastomer present in the organic medium.

In another embodiment, the aqueous medium comprises 500 ppm or less,preferably 200 ppm or less, more preferably 100 ppm or less, even morepreferably 20 ppm or less and yet even more preferably 10 ppm or lessand in another yet even more preferred embodiment 5 ppm or less and yeteven more preferably no dispersants, emulsifiers or anti-agglomerantsother than the LCST compounds.

The term “plurality” denotes an integer of at least two, preferably atleast 20, more preferably at least 100.

In one embodiment the expression “aqueous slurry comprising a pluralityof halogenated elastomer particles suspended therein” denotes a slurryhaving at least 10 discrete particles per liter suspended therein,preferably at least 20 discrete particles per liter, more preferably atleast 50 discrete particles per liter and even more preferably at least100 discrete particles per liter.

The term halogenated elastomer particles denote discrete particles ofany form and consistency, which in a preferred embodiment have aparticle size of between 0.05 mm and 25 mm, more preferably between 0.1and 20 mm.

In one embodiment the weight average particle size of the halogenatedelastomer particles is from 0.3 to 10.0 mm.

It is apparent to those skilled in the art, that the halogenatedelastomer particles formed according to the invention may still containorganic diluent and further may contain water encapsulated within thehalogenated elastomer particle. In one embodiment the halogenatedelastomer particles contain 90 wt.-% or more of the halogenatedelastomer calculated on the sum of organic diluent and halogenatedelastomer, preferably 93 wt.-% or more, more preferably 94 wt.-% or moreand even more preferably 96 wt.-% or more.

As mentioned above halogenated elastomer particles are often referred toas crumbs in the literature. Typically the halogenated elastomerparticles or crumbs have non-uniform shape and/or geometry.

The term aqueous medium denotes a medium comprising 80 wt.-% or more ofwater, preferably 90 wt.-% or more 80 wt.-% and even more preferably 95wt.-% or more of water and yet even more preferably 99 wt.-% or more.

The remainder to 100 wt.-% includes the LCST compounds and may furtherinclude compounds selected from the group of

-   -   non-LCST compounds as defined above    -   compounds and salts which are neither an LCST compound nor a        non-LCST compound as defined above    -   organic diluents to the extent dissolvable in the aqueous medium    -   where an extended shelf life of the product is desired        antioxidants and/or stabilizers.

In one embodiment the aqueous phase comprises of from 1 to 2,000 ppm ofantioxidants, preferably of from 50 to 1,000 ppm more preferably of from80 to 500 ppm calculated with respect to the amount of halogenatedelastomer present in the organic medium.

Where desired to obtain very high purity halogenated elastomers thewater employed to prepare the aqueous phase is demineralized by standardprocedure such as ion-exchange, membrane filtration techniques such asreverse osmosis and the like.

Typically application of water having a degree of 8.0 german degrees ofhardness (° dH) hardness or less, preferably 6.0° dH or less, morepreferably 3.75° dH or less and even more preferably 3.00° dH or less issufficient.

In one embodiment the water is mixed with the at least one LCSTcompounds to obtain a concentrate which is depending on the temperatureeither a slurry or a solution having a LCST-compound concentration offrom 0.1 to 2 wt.-%, preferably 0.5 to 1 wt.-%. This concentrate is thenmetered into and diluted with more water in the vessel in which step A)is performed to the desired concentration.

Preferably the concentrate is a solution and metered into the vesselhaving a temperature of from 0 to 35° C., preferably 10 to 30° C.

If not mentioned otherwise, ppm refer to weight.-ppm.

The aqueous medium may further contain antioxidants and/or stabilizers:

Antioxidants and stabilizers include 2,6-di-tert.-butyl-4-methyl-phenol(BHT) andpentaerythrol-tetrakis-[3-(3,5-di-tert.-butyl-4-hydroxyphenyl)-propanoicacid (also known as Irganox® 1010), octadecyl3,5-di(tert)-butyl-4-hydroxyhydrocinnamate (also known as Irganox®1076), tert-butyl-4-hydroxy anisole (BHA),2-(1,1-dimethyl)-1,4-benzenediol (TBHQ),tris(2,4,-di-tert-butylphenyl)phosphate (Irgafos® 168),dioctyldiphenylamine (Stalite® S), butylated products of p-cresol anddicyclopentadiene (Wingstay) as well as other phenolic antioxidants andhindered amine light stabilizers.

Suitable antioxidants generally include 2,4,6-tri-tert-butylphenol,2,4,6 tri-isobutylphenol, 2-tert-butyl-4,6-dimethylphenol,2,4-dibutyl-6-ethylphenol, 2,4-dimethyl-6-tert-butylphenol,2,6-di-tert-butylhydroyxytoluol (BHT), 2,6-di-tert-butyl-4-ethylphenol,2,6-di-tert-butyl-4-n-butylphenol, 2,6-di-tert-butyl-4-iso-butylphenol,2,6-dicyclopentyl-4-methylphenol, 4-tert-butyl-2,6-dimethylphenol,4-tert-butyl-2,6-dicyclopentylphenol,4-tert-butyl-2,6-diisopropylphenol, 4,6-di-tert-butyl-2-methylphenol,6-tert-butyl-2,4-dimethylphenol, 2,6-di-tert-butyl-3-methylphenol,4-hydroxymethyl-2,6-di-tert-butylphenol,2,6-di-tert-butyl-4-phenylphenol and 2,6-dioctadecyl-4-methylphenol,2,2′-ethylidene-bis[4,6-di-tert.-butylphenol],2,2′-ethylidene-bis[6-tert.-butyl-4-isobutylphenol],2,2′-isobutylidene-bis[4,6-dimethyl-phenol],2,2′-methylene-bis[4,6-di-tert.-butylphenol],2,2′-methylene-bis[4-methyl-6-(α-methylcyclohexyl)phenol],2,2′-methylene-bis[4-methyl-6-cyclohexylphenol],2,2′-methylene-bis[4-methyl-6-nonylphenol],2,2′-methylene-bis[6-(α,α-dimethylbenzyl)-4-nonylphenol],2,2′-methylene-bis[6-(α-methylbenzyl)-4-nonylphenol],2,2′-methylene-bis[6-cyclohexyl-4-methylphenol],2,2′-methylene-bis[6-tert.-butyl-4-ethylphenol],2,2′-methylene-bis[6-tert.-butyl-4-methylphenol],4,4′-butylidene-bis[2-tert.-butyl-5-methylphenol],4,4′-methylene-bis[2,6-di-tert.-butylphenol],4,4′-methylene-bis[6-tert.-butyl-2-methylphenol],4,4′-isopropylidene-diphenol, 4,4′-decylidene-bisphenol,4,4′-dodecylidene-bisphenol, 4,4′-(1-methyloctylidene)bisphenol,4,4′-cyclohexylidene-bis(2-methylphenol), 4,4′-cyclohexylidenebisphenol,andpentaerythrol-tetrakis-[3-(3,5-di-tert.-butyl-4-hydroxyphenyl)-propanoicacid (also known as Irganox® 1010).

Suitable stabilizers, in particular for brominated elastomers includeepoxidized unsaturated oils such as epoxidized linseed oil or epoxidizedsoybean oil, whereby the latter is preferred.

Antioxidants and/or stabilizers may, in one embodiment, be alternativelyor additionally also present or added to the organic medium beforeperforming step A).

In one embodiment antioxidants are added to the aqueous medium and thestabilizers are present or are added to the organic medium.

In one embodiment the weight average molecular weight of the halogenatedelastomer is in the range of from 10 to 2,000 kg/mol, preferably in therange of from 20 to 1,000 kg/mol, more preferably in the range of from50 to 1,000 kg/mol, even more preferably in the range of from 200 to 800kg/mol, yet more preferably in the range of from 375 to 550 kg/mol, andmost preferably in the range of from 400 to 500 kg/mol. Molecularweights are obtained using gel permeation chromatography intetrahydrofuran (THF) solution using polystyrene molecular weightstandards if not mentioned otherwise.

In one embodiment the polydispersity of the halogenated elastomersaccording to the invention is in the range of 1.5 to 4.5 as measured bythe ratio of weight average molecular weight to number average molecularweight as determined by gel permeation chromatography.

The halogenated elastomer for example and typically has a Mooneyviscosity of at least 10 (ML 1+8 at 125° C., ASTM D 1646), preferably offrom 10 to 80, more preferably of from 20 to 80 and even more preferablyof from 25 to 60 (ML 1+8 at 125° C., ASTM D 1646).

Halogenation

In one embodiment the organic medium employed in step A) is obtained bya process comprising at least the step of:

-   -   i) halogenating an elastomer using a halogenating agent in a        organic diluent to obtain an organic medium comprising the        halogenated elastomer and the organic diluent and optionally    -   ii) washing the organic medium comprising the halogenated        elastomer with a basic aqueous phase and separating the        resulting aqueous phase from the organic medium.

As used herein “basic” means that the ageous phase has a pH value of 7,5to 13, preferably 8 to 12, more preferably 8 to 11 and even morepreferably 9 to 10

In one embodiment the halogenated elastomer is obtained by halogenatingan elastomer comprising repeating units derived from at least oneisoolefin and repeating units of at least one multiolefin.

As used herein the term isoolefins denotes compounds comprising onecarbon-carbon-double-bond, wherein one carbon-atom of the double-bond issubstituted by two alkyl-groups and the other carbon atom is substitutedby two hydrogen atoms or by one hydrogen atom and one alkyl-group.

Examples of suitable isoolefins include isoolefin monomers having from 4to 16 carbon atoms, preferably 4 to 7 carbon atoms, such as isobutene,2-methyl-1-butene, 3-methyl-1-butene, 2-methyl-2-butene. A preferredisolefin is isobutene.

As used herein the term multiolefin denotes compounds comprising morethan one carbon-carbon-double-bond, either conjugated or non-conjugated.

Examples of suitable multiolefins include isoprene, butadiene,2-methylbutadiene, 2,4-dimethylbutadiene, piperyline,3-methyl-1,3-pentadiene, 2,4-hexadiene, 2-neopentylbutadiene,2-methyl-1,5-hexadiene, 2,5-dimethyl-2,4-hexadiene,2-methyl-1,4-pentadiene, 4-butyl-1,3-pentadiene,2,3-dimethyl-1,3-pentadiene, 2,3-dibutyl-1,3-pentadiene,2-ethyl-1,3-pentadiene, 2-ethyl-1,3-butadiene, 2-methyl-1,6-heptadiene,cyclopentadiene, methylcyclopentadiene, cyclohexadiene and1-vinyl-cyclohexadiene.

Preferred multiolefins are isoprene and butadiene. Isoprene isparticularly preferred.

The elastomers used for halogenation may further comprise furtherolefins which are neither isoolefins nor multiolefins.

Examples of such suitable olefins include β-pinene, styrene,divinylbenzene, diisopropenylbenzene o-, m- and p-alkylstyrenes such aso-, m- and p-methyl-styrene.

The multiolefin content of elastomers is typically 0.1 mol-% or more,preferably of from 0.1 mol-% to 15 mol-%, in another embodiment 0.5mol-% or more, preferably of from 0.5 mol-% to 10 mol-%, in anotherembodiment 0.7 mol-% or more, preferably of from 0.7 to 8.5 mol-% inparticular of from 0.8 to 1.5 or from 1.5 to 2.5 mol-% or of from 2.5 to4.5 mol-% or from 4.5 to 8.5 mol-%, particularly where isobutene andisoprene are employed.

In step i) the elastomer is halogenated.

Preferably, the amount of halogenating agent is in the range of fromabout 0.1 to about 20%, preferably in the range of 0.1 to 8%, even morepreferably from about 0.5% to about 4%, yet even more preferably fromabout 0.8% to about 3%, even still more preferably from about 1.5% toabout 2.5% and most preferably even more preferably from 1.5 to 2,5% byweight of the elastomer employed.

In another embodiment the quantity of halogenating agent is 0.2 to 1.2times the molar quantity of double bonds contained in the elastomer,preferably 0.8 to 1.2 times the molar quantity.

The halogenating agent may comprise elemental bromine (Br₂), elementalchlorine (Cl₂) interhalogens such as bromine chloride (BrCl) and/ororgano-halide precursors thereto, for example dibromo-dimethylhydantoin, N-bromosuccinimide, or the like. The most preferredbromination agent comprises elemental bromine, the most preferredchlorinating agent elemental chlorine.

The halogenation process may be operated at a temperature of from 10° C.to 90° C., preferably from 20° C. to 80° C. and the reaction time may befrom 1 to 10 minutes, preferably from 1 to 5 minutes. The pressure inthe bromination reactor may be from 0.8 to 10 bar.

The level of halogenation during this procedure may be controlled sothat the final halogenated elastomer has the preferred amounts ofhalogen described hereinabove. The specific mode of attaching thehalogen to the polymer is not particularly restricted and those of skillin the art will recognize that modes other than those described abovemay be used while achieving the benefits of the invention. Foradditional details and alternative embodiments of solution phasebromination processes, see, for example, Ullmann's Encyclopedia ofIndustrial Chemistry (Fifth, Completely Revised Edition, Volume A231Editors Elvers, et al.) and/or “Rubber Technology” (Third Edition) byMaurice Morton, Chapter 10 (Van Nostrand Reinhold Company© 1987),particularly pp. 297-300, which are incorporated herein by reference.

Organic Diluents

The term organic diluent encompasses diluting or dissolving organicchemicals which are liquid under process conditions. Any suitableorganic diluent may be used which does not or not to any appreciableextent react with halogenated elastomers.

Additionally, the term organic diluent includes mixtures of at least twodiluents.

Preferred examples of organic diluents include hydrocarbons, preferablyalkanes which in a further preferred embodiment include propane,isobutane, pentane, methycyclopentane, isohexane, 2-methylpentane,3-methylpentane, 2-methylbutane, 2,2-dimethylbutane, 2,3-dimethylbutane,2-methylhexane, 3-methylhexane, 3-ethylpentane, 2,2-dimethylpentane,2,3-dimethylpentane, 2,4-dimethylpentane, 3,3-dimethyl pentane,2-methylheptane, 3-ethylhexane, 2,5-dimethylhexane,2,2,4,-trimethylpentane, octane, heptane, butane, ethane, methane,nonane, decane, dodecane, undecane, hexane, methyl cyclohexane,cyclopropane, cyclobutane, cyclopentane, methylcyclopentane,1,1-dimethylcycopentane, cis-1,2-dimethylcyclopentane,trans-1,2-dimethylcyclopentane, trans-1,3-dimethyl-cyclopentane,ethylcyclopentane, cyclohexane, methylcyclohexane.

Examples of organic diluents include hydrochlorocarbons, preferablyhalogenated alkanes such as dichloromethane.

Suitable organic diluents further include mixtures of at least twocompounds selected from the groups of hydrochlorocarbons andhydrocarbons.

The concentration of halogenated elastomer within the organic medium isfor example of from 0.5 to 40 wt.-%, preferably of from 1 to 30 wt.-%,more preferably of from 5 to 25 wt.-%.

In step A) the organic medium, for example those obtained according tostep i), is contacted with an aqueous medium comprising at least oneLCST compound having a cloud point of 0 to 100° C., preferably 5 to 100°C., more preferably 15 to 80° C. and even more preferably 20 to 70° C.and removing at least partially the organic diluent to obtain theaqueous slurry comprising the plurality halogenated elastomer particles.

The contact can be performed in any vessel suitable for this purpose. Inindustry such contact is typically performed in a flash drum or anyother vessel known for separation of a liquid phase and vapours.

Removal of organic diluent may also employ other types of distillationso to subsequently or jointly remove the residual monomers and theorganic diluent to the desired extent. Distillation processes toseparate liquids of different boiling points are well known in the artand are described in, for example, the Encyclopedia of ChemicalTechnology, Kirk Othmer, 4th Edition, pp. 8-311, which is incorporatedherein by reference. Generally, the organic diluent may either beseparately or jointly be recycled into a step i) of a halogenationreaction.

The pressure in step A) and in one embodiment the steam-stripper orflash drum depends on the organic diluent but is typically in the rangeof from 100 hPa to 5,000 hPa.

The temperature in step A) is selected to be sufficient to at leastpartially remove the organic diluent.

In one embodiment the temperature is from 10 to 100° C., preferably from50 to 100° C., more preferably from 60 to 95° C. and even morepreferably from 75 to 95° C.

Upon contact of the organic medium with the aqueous medium comprising atleast one LCST compound halogenated elastomer particles suspended in theaqueous slurry are formed.

According to the observations of the applicant and without wanting to bebound by theory a further consequence is that the at least LCST compoundas earlier observed for conventional anti-agglomerants such as calciumstearate, the aqueous medium comprising the at least one LCST compounddepletes from LCST compounds so that in the final aqueous slurry atleast a part, according to the observations disclosed in theexperimental part a substantial part of the LCST compounds are part ofthe halogenated elastomer particles and are presumably bound to thesurface of the halogenated elastomer particles causing the tremendousanti-agglomerating effect.

Suitable LCST compounds are for example selected from the groupconsisting of:

poly(N-isopropylacrylamide), poly(N-isopropylacrylamide-co-N,N-dimethylacrylamide,poly(N-isopropylacrylamide)-alt-2-hydroxyethylmethacrylate,poly(N-vinylcaprolactam), poly(N,N-diethylacrylamide),poly[2-(dimethylamino)ethyl methacrylate], poly(2-oxazoline)glyhalogenated elastomers, Poly(3-ethyl-N-vinyl-2-pyrrolidone),hydroxylbutyl chitosan, polyoxyethylene (20) sorbitan monostearate,polyoxyethylene (20) sorbitan monolaurate, polyoxyethylene (20) sorbitanmonooleate, methyl cellulose, hydroxypropyl cellulose, hydroxyethylmethylcellulose, hydroxypropyl methylcellulose, poly(ethylene glycol)methacrylates with 2 to 6 ethylene glycol units,polyethyleneglycol-co-polypropylene glycols, preferably those with 2 to6 ethylene glycol units and 2 to 6 polypropylene units, compounds offormula (I)

HO—[—CH₂—CH₂—O]_(x)—[—CH(CH₃)—CH₂—O]_(y)—[—CH₂—CH₂—O]_(z)—H  (I)

with y=3 to 10 and x and z=1 to 8, whereby y+x+z is from 5 to 18,polyethyleneglycol-co-polypropylene glycol, preferably those with 2 to 8ethylene glycol units and 2 to 8 polypropylene units, ethoxylatediso-C₁₃H₂₇-alcohols, preferably with an ethoxylation degree of 4 to 8,polyethylene glycol with 4 to 50, preferably 4 to 20 ethyleneglycolunits, polypropylene glycol with 4 to 30, preferably 4 to 15propyleneglycol units, polyethylene glycol monomethyl, dimethyl,monoethyl and diethyl ether with 4 to 50, preferably 4 to 20ethyleneglycol units, polypropylene glycol monomethyl, dimethyl,monoethyl and diethyl ether with 4 to 50, preferably 4 to 20propyleneglycol units, whereby in another embodiment the aforementionedLCST compounds additionally include hydroxyethylcellulose and wherebymethyl cellulose, hydroxypropyl cellulose, hydroxyethyl methylcelluloseand hydroxypropyl methylcellulose are preferred.

In one embodiment methyl cellulose, hydroxypropyl cellulose,hydroxyethyl methylcellulose and hydroxypropyl methylcellulose have adegree of substitution of from 0.5 to 2.8 the theoretical maximum being3, preferably 1.2 to 2.5 and more preferably 1.5 to 2.0.

In one embodiment hydroxypropyl cellulose, hydroxyethyl methylcelluloseand hydroxypropyl methylcellulose have a MS (moles of substitution) offrom 3, preferably of from 4, more preferably of from 4 to 20 withrespect to ethylene glycol or propylene glycol groups per glucose unit.

The amount of LCST compound(s) present in the aquous medium employed instep A) is for example of from 1 to 20,000 ppm, preferably 3 to 10,000ppm, more preferably 5 to 5,000 ppm and even more preferably 10 to 5,000ppm with respect to the amount of halogenated elastomer present in theorganic medium.

In one embodiment the LCST compounds exhibit a molecular weight of atleast 1,500 g/mol, preferably at least 2,500 g/mol and more preferablyat least 4,000 g/mol.

Where a mixture of different LCST compounds is applied the weightaverage molecular weight is for example of from 1,500 to 2,000,000.

The unique capability of the LCST compounds to stabilize halogenatedelastomer particles in aqueous solution is a major finding of theinvention. The invention therefore also encompasses a method to preventor reduce or to slow-down agglomeration of slurries comprisinghalogenated elastomer particles suspended in aqueous media by additionor use of LCST compounds having a cloud point of 0 to 100° C.,preferably 5 to 100° C., more preferably 15 to 80° C. and even morepreferably 20 to 70° C.

For the avoidance of doubt it is noted that the aqueous slurry obtainedin step A) is distinct from and unrelated to the polymerization slurrythat may be obtained in some embodiments described in step b).

In case step b) was carried out as solution polymerization upon contactwith water the organic diluent is evaporated and the halogenatedelastomer forms halogenated elastomer particles suspended in the aqueousslurry.

The at least partial removal of the organic diluent typically requiressignificant amounts of heat to balance the heat of evaporation which canbe provided for example by heating the vessel wherein step A) isperformed either from outside or in a preferred embodiment additionallyor alternatively by introducing steam which further aids removal oforganic diluent and to the extent still present after polymerization themonomers (steam stripping).

Step A) may be carried out batchwise or continuously, whereby acontinuous operation is preferred.

In one embodiment the temperature of the resulting slurry obtained instep A) is from 50 to 100° C., preferably from 60 to 100° C., morepreferably from 70 to 95° C. and even more preferably from 75 to 95° C.

Even found not to be necessary in one embodiment the temperature in stepA) is above the highest determined cloud point of the at least one LCSTcompound employed.

Highest determined cloud point means the highest cloud point measuredwith the three methods disclosed above. If a cloud point cannot bedetermined for whatever reason with one or two methods the highest cloudpoint of the other determinations is taken as the highest determinedcloud point.

In one embodiment the removal of the organic diluent is performed untilthe aqueous slurry comprises less than 10 wt.-% of organic diluentcalculated on the halogenated elastomer contained in the halogenatedelastomer particles of the resulting aqueous slurry, preferably lessthan 7 wt.-% and even more preferably less than 5 wt.-% and yet evenmore preferably less than 3 wt.-%.

It was not known before and is highly surprising that an aqueous slurrycomprising a plurality of halogenated elastomer particles with very lowlevels or even absence of antiagglomerants selected from carboxylic acidsalts of mono- or multivalent metal ions and layered minerals can beobtained at all.

Therefore, the use of LCST compounds having a cloud point of 0 to 100°C., preferably 5 to 100° C., more preferably 15 to 80° C. and even morepreferably 20 to 70° C. as anti-agglomerant, in particular forhalogenated elastomer particles as defined is encompassed by theinvention as well.

The aqueous slurries disclosed hereinabove and as obtainable accordingto step A) as such are therefore also encompassed by the invention.

The aqueous slurries obtained according to step A) serve as an idealstarting material to obtain the halogenated elastomer particles inisolated form.

Therefore, in a further step C) the halogenated elastomer particlescontained in the aqueous slurry obtained according to step B) may beseparated to obtain the halogenated elastomer particles.

The separation may be effected by flotation, centrifugation, filtration,dewatering in a dewatering extruder or by any other means known to thoseskilled in the art for the separation of solids from fluids.

In one embodiment the separated aqueous phase is recycled into step A)if required after replacement of LCST-compounds, water and optionallyother components which were removed with the halogenated elastomerparticles.

In a further step D) the halogenated elastomer particles obtainedaccording to step C) are dried, preferably to a residual content ofvolatiles of 7,000 or less, preferably 5,000 or less, even morepreferably 4,000 or less and in another embodiment 2,000 ppm or less,preferably 1,000 ppm or less.

It has been observed that after step D, material produced according tothe invention without the use of calcium stearate shows reduced fines inthe finishing process when compared to material produced according tostandard methods. Reducing fines shows advantages in fouling and reducedcleaning frequency required in step D).

Where desired, e.g. to produce perform-alike products having usuallevels of multivalent stearates or palmitates, in particular calciumstearate and palmitate or zinc stearate and palmitate, these multivalentstearates or palmitates may be added to the halogenated elastomerparticles obtained according to the invention e.g. at step C) or D),preferably step C). This may be effected e.g. in step e) by sprayingaqueous suspensions of said multivalent stearates and/or palmitates ontothe halogenated elastomer particles. Multivalent stearates and/orpalmitates, in particular calcium and/or zinc stearate and/or palmitatemay also be added at any point or step after the formation of theaqueous slurry of halogenated copolymer particles according to steps A)and B).

It is also possible to realize certain advantages of the LCST agents byadding at least one LCST agent to a production process usinganti-agglomerants known in the prior art for steps A) and B): Inparticular agglomeration of halogenated elastomer particles in anaqueous slurries produced through use of multivalent stearates and/orpalmitates such as calcium and/or zinc stearate and/or palmitate can besubstantially delayed through the addition of at least one LCST agentafter formation of halogenated rubber particles.

As a consequence the invention encompasses also the general use of LCSTcompounds, including their preferred embodiments, in processing ofhalogenated elastomer particles.

As used herein the term volatiles denotes compounds having a boilingpoint of below 250° C., preferably 200° C. or less at standard pressureand include water as well as remaining organic diluents.

Drying can be performed using conventional means known to those in theart, which includes drying on a heated mesh conveyor belt.

Depending on the drying process the halogenated elastomer particles mayalso be brought into a different shape hereinafter referred to ashalogenated elastomer products. Halogenated elastomer products are forexample pellets.

However the term halogenated elastomer products encompasses any type ofhalogenated elastomer irrespective of its shape as long as the parameterdefined herein are fulfilled.

Such halogenated elastomer products are also encompassed by theinvention and for example obtained by drying in an extruder followed bypelletizing at the extruder outlet. Such pelletizing may also beperformed under water. The process according to the invention allowspreparation of halogenated elastomer particles and halogenated elastomerproducts having a tunable or if desired an unprecedented low level ofmono- and multivalent metal ions.

The invention therefore encompasses halogenated elastomer particles andhalogenated elastomer products having a halogenated elastomer content of98.5 wt.-% or more, preferably 98.8 wt.-% or more, more preferably, 99.0wt.-% or more even more preferably 99.2 wt.-% or more, yet even morepreferably 99.4 wt.-% or more and in another embodiment 99.5 wt.-% ormore preferably 99.7 wt.-% or more.

In one embodiment the halogenated elastomer particles or the halogenatedelastomer products comprise 550 ppm or less, preferably 400 ppm or less,more preferably 300 ppm or less, even more preferably 250 ppm or lessand yet even more preferably 150 ppm or less and in another yet evenmore preferred embodiment 100 ppm or less of salts of mono- ormultivalent metal ions calculated on their metal content and withrespect to the amount of halogenated elastomer present in the organicmedium.

In one embodiment the halogenated elastomer particles or the halogenatedelastomer products comprise 5000 ppm or less, preferably 2.000 ppm orless, more preferably 1.000 ppm or less, even more preferably 500 ppm orless and yet even more preferably 100 ppm or less and in another yeteven more preferred embodiment 50 ppm or less, preferably 50 ppm or lessmore preferably 10 ppm or less and yet even more preferably no non-LCSTcompounds whereby the non-LCST compounds are

-   -   selected from the group consisting of ionic or non-ionic        surfactants, emulsifiers, and antiagglomerants or are in another        embodiment    -   salts of (mono- or multivalent) metal ions or are in another        embodiment    -   carboxylic acid salts of multivalent metal ions or are in        another embodiment    -   stearates or palmitates of mono- or multivalent metal ions or        are in another embodiment    -   calcium and zinc stearates or palmitates.

In another aspect the invention provides halogenated elastomer particlesor the halogenated elastomer products comprising salts of multivalentmetal ions in an amount of 500 ppm or less, preferably 400 ppm or less,more preferably 250 ppm or less, even more preferably 150 ppm or lessand yet even more preferably 100 ppm or less and in an even morepreferred embodiment 50 ppm or less calculated on their metal content.

The halogenated elastomer particles or the halogenated elastomerproducts may further comprise antioxidants such as2,6-di-tert.-butyl-4-methyl-phenol (BHT) andpentaerythrol-tetrakis-[3-(3,5-di-tert.-butyl-4-hydroxyphenyl)-propanoicacid (also known as Irganox® 1010), for example in an amount of from 50ppm to 1000 ppm, preferably of from 80 ppm to 500 ppm and in anotherembodiment of from 300 ppm to 700 ppm.

The halogenated elastomer particles or the halogenated elastomerproducts may further comprise stabilizers, in particular for brominatedelastomers such as epoxidized unsaturated oils such as epoxidizedlinseed oil or epoxidized soybean oil, whereby the latter is preferred.Such stabilizers are for example present in an amount of from 0.05 to2.50 wt.-%, preferably 0.20 to 1.50 wt.-% and in another embodiment offrom 0.50 to 1.50 wt.-%.

Typically the remainder to 100 wt.-% include the LCST compound(s),volatiles, to the extent employed at all salts of multivalent metal ionsas well as low levels of residual monovalent metal ion salts such assodium chloride.

In one embodiment the amount of LCST compounds present in thehalogenated elastomer particles or the halogenated elastomer products isfrom 1 ppm to 18,000 ppm, preferably of from 1 ppm to 10,000 ppm, morepreferably 1 ppm to 5,000 ppm, even more preferably from 1 ppm to 2,000ppm and in a more preferred embodiment from 5 to 1,000 ppm or from 5 to500 ppm.

In one embodiment the amount of salts of monovalent metal ions presentin the halogenated elastomer particles or the halogenated elastomerproducts is from 1 ppm to 1,000 ppm, preferably from 10 ppm to 500 ppmand in a more preferred embodiment from 10 to 200 ppm.

In one embodiment the amount of stearates or palmitates of mono- ormultivalent metal ions present in the halogenated elastomer particles orthe halogenated elastomer products is 0 to 4,000 ppm, preferably 0 to2,000 ppm, more preferably 0 to 1,000 ppm and in a more preferredembodiment from 0 to 500 ppm.

In one embodiment the amount of LCST compounds present in thehalogenated elastomer particles or the halogenated elastomer products isfrom 1 ppm to 5,000 ppm, preferably from 1 ppm to 2,000 ppm and in amore preferred embodiment from 5 to 1,000 ppm or from 5 to 500 ppm.

In another preferred embodiment the amount of LCST compounds present inthe halogenated elastomer particles or the halogenated elastomerproducts is from 5 to 100 ppm, preferably from 5 to 50 ppm and morepreferably from 5 to 30 ppm.

In one embodiment the amount of salts of monovalent metal ions presentin the halogenated elastomer particles or the halogenated elastomerproducts is from 1 ppm to 1,000 ppm, preferably from 10 ppm to 500 ppmand in a more preferred embodiment from 10 to 200 ppm.

In one embodiment the amount of stearates or palmitates of multivalentmetal ions present in the halogenated elastomer particles or thehalogenated elastomer products is 0 to 4,000 ppm, preferably 0 to 2,000ppm, more preferably 0 to 1,000 ppm and in a more preferred embodimentfrom 0 to 500 ppm.

In one embodiment the invention therefore encompasses halogenatedelastomer particles or the halogenated elastomer products comprising

-   -   I) 96.0 wt.-% or more, preferably 97.0 wt.-% or more, more        preferably, 98.0 wt.-% or more even more preferably 99.0 wt.-%        or more, yet even more preferably 99.2 wt.-% or more and in        another embodiment 99.5 wt.-% or more of a halogenated elastomer    -   II) 0 to 3.0 wt.-%, preferably 0 to 2.5 wt.-%, more preferably 0        to 1.0 wt.-% and more preferably 0 to 0.40 wt.-% of salts of        mono- or multivalent metal ions, preferably stearates and        palmitates of multivalent metal ions and    -   III) 1 ppm to 5,000 ppm, preferably from 1 ppm to 2,000 ppm and        in a more preferred embodiment from 5 to 1,000 ppm or from 5 to        500 ppm of at least one LCST compound.

In yet another embodiment the invention encompasses (reshaped)halogenated elastomer particles comprising

-   -   I) 100 parts by weight of a halogenated elastomer    -   II) 0.0001 to 0.5, preferably 0.0001 to 0.2, more preferably        0.0005 to 0.1, even more preferably 0.0005 to 0.05 parts by        weight of a least one LCST compound and    -   III) no or from 0.0001 to 3.0, preferably no or from 0.0001 to        2.0, more preferably no or from 0.0001 to 1.0, even more        preferably no or from 0.0001 to 0.5, yet even more preferably no        or from 0.0001 to 0.3, and most preferably no or from 0.0001 to        0.2 parts by weight of salts of mono- or multivalent metal ions,        preferably stearates and palmitates of mono- or multivalent        metal ions, preferably comprising calcium stearate, calcium        palmitate, zinc stearate or zinc palmitate and    -   IV) no or from 0.005 to 0.3, preferably 0.05 to 0.1, more        preferably from 0.008 to 0.05 and yet more preferably from 0.03        to 0.07 parts by weight of antioxidants    -   V) from 0.005 to 1.5, preferably 0.05 to 1.0, more preferably        0.005 to 0.5, even more preferably from 0.01 to 0.3 and yet even        more preferably from 0.05 to 0.2 parts by weight of volatiles        having a boiling point at standard pressure of 200° C. or less.

In another embodiment halogenated elastomer particles or the halogenatedelastomer products further comprise

-   -   VI) from 0.05 to 2.5, preferably from 0.20 to 1.50, more        preferably from 0.50 to 1.50 parts by weight and even more        preferably 0.75 to 1.50 parts by weight of stabilizers,        preferably epoxidized compounds, preferably epoxidized        unsaturated oils such as epoxidized linseed oil or epoxidized        soybean oil, whereby the latter is preferred.

Preferably the aforementioned components I) to V) add up to 100.00501 to105.300000 parts by weight, preferably 100.00501 to 104.100000 parts byweight, more preferably from 100.01 to 103.00 parts by weight, even morepreferably from 100.10 to 101.50 parts by weight, yet even morepreferably from 100.10 to 100.80 parts by weight and together represent99.50 to 100.00 wt.-% or, in another embodiment, 99.80 to 100.00 wt.-%,preferably 99.90 to 100.00 wt.-%, more preferably 99.95 to 100.00 wt.-%and yet even more preferably 99.97 to 100.00 wt.-% of the total weightof the halogenated elastomer particles or halogenated elastomer product.

In another embodiment the aforementioned components I) to VI) add up to100.05501 to 107.800000 parts by weight, preferably 100.05501 to106.600000 parts by weight, preferably from 100.21 to 104.50 parts byweight, more preferably from 100.60 to 103.00 parts by weight, even morepreferably from 100.85 to 102.30 parts by weight and together represent99.50 to 100.00 wt.-% or, in another embodiment, 99.80 to 100.00 wt.-%,preferably 99.90 to 100.00 wt.-%, more preferably 99.95 to 100.00 wt.-%and yet even more preferably 99.97 to 100.00 wt.-% of the total weightof the halogenated elastomer particles or halogenated elastomer product.

The remainder, if any, may represent salts or components which are noneof the aforementioned components and e.g. stemming from the wateremployed to prepare the aqueous phase used in step A) or othercomponents stemming e.g. from post-polymerization modifications.

Since salts of multivalent metal ions contribute to the ash contentmeasurable according to ASTM D5667 (reapproved version 2010) theinvention further encompasses halogenated elastomer particles andhalogenated elastomer products comprising 97.5 wt.-% or more, preferably98.0 wt.-% or more, more preferably, 98.2 wt.-% or more even morepreferably 98.4 wt.-% or more, yet even more preferably 98.5 wt.-% ormore and in another embodiment 99.5 wt.-% or more of a halogenatedelastomer and having an ash content measured according to ASTM D5667 of0.25 wt.-% or less, preferably 0.15 wt.-% or less, more preferably 0.10wt.-% or less and even more preferably 0.05 wt.-% or less.

In a preferred embodiment the aforementioned copolymer composition, inparticular halogenated elastomer particles and halogenated elastomerproducts further comprise 1 ppm to 5,000 ppm, preferably from 1 ppm to2,000 ppm and in a more preferred embodiment from 5 to 1,000 ppm or from5 to 500 ppm of a least one LCST compound.

For all halogenated elastomer particles and halogenated elastomerproducts described above and hereinbelow in one embodiment, additionallythe ash content measured according to ASTM D5667 is for example 0.25wt.-% or less, preferably 0.15 wt.-% or less, more preferably 0.10 wt.-%or less and even more preferably 0.05 wt.-% or less.

In yet another embodiment the invention encompasses halogenatedelastomer particles or the halogenated elastomer products comprising

-   -   I) 96.0 wt.-% or more, preferably 97.0 wt.-% or more, more        preferably, 98.0 wt.-% or more even more preferably 99.0 wt.-%        or more, yet even more preferably 99.2 wt.-% or more and in        another embodiment 99.5 wt.-% or more of a halogenated elastomer        and    -   II) 1 ppm to 5,000 ppm, preferably from 1 ppm to 2,000 ppm and        in a more preferred embodiment from 5 to 1,000 ppm or from 5 to        500 ppm of at least one LCST compound,        whereby the halogenated elastomer particles or the halogenated        elastomer products further have an ash content measured        according to ASTM D5667 of 0.25 wt.-% or less, preferably 0.15        wt.-% or less, more preferably 0.10 wt.-% or less and even more        preferably 0.05 wt.-% or less.

In yet another embodiment the invention encompasses halogenatedelastomer particles or the halogenated elastomer products comprising

-   -   I) 100 parts by weight of a halogenated elastomer (phr)    -   II) 0.0001 to 0.5, preferably 0.0001 to 0.2, more preferably        0.0005 to 0.1, even more preferably 0.0005 to 0.05 parts by        weight (phr) of a least one LCST compound and    -   III) no or from 0.005 to 0.3, preferably 0.005 to 0.1, more        preferably from 0.008 to 0.05, even more preferably from 0.03 to        0.07 parts by weight (phr) of antioxidants    -   IV) from 0.005 to 1.5, preferably 0.05 to 1.0, more preferably        0.005 to 0.5, even more preferably from 0.01 to 0.3 and yet more        preferably from 0.05 to 0.2 parts by weight (phr) of volatiles        having a boiling point at standard pressure of 200° C. or less        whereby the halogenated elastomer particles or the halogenated        elastomer products further have an ash content measured        according to ASTM D5667 of 0.25 wt.-% or less, preferably 0.15        wt.-% or less, more preferably 0.10 wt.-% or less and even more        preferably 0.05 wt.-% or less.

In another embodiment the aforementioned halogenated elastomer particlesor the halogenated elastomer products further comprise

-   -   V) from 0.05 to 2.5, preferably from 0.20 to 1.50, more        preferably from 0.50 to 1.50 parts by weight and even more        preferably 0.75 to 1.50 parts by weight of stabilizers,        preferably epoxidized compounds, preferably epoxidized        unsaturated oils such as epoxidized linseed oil or epoxidized        soybean oil, whereby the latter is preferred.

Preferably the aforementioned components I) to IV) add up to 100.00501to 102.300000 parts by weight and together represent 99.00 to 100.00wt.-% or, in another embodiment, 99.50 to 100.00 wt.-%, preferably 99.70to 100.00 wt.-% of the total weight of the halogenated elastomerparticles or halogenated elastomer product.

In another embodiment the aforementioned components I) to V) add up to100.05501 to 105.800000 parts by weight and together represent 99.00 to100.00 wt.-% or, in another embodiment, 99.50 to 100.00 wt.-%,preferably 99.70 to 100.00 wt.-% of the total weight of the halogenatedelastomer particles or halogenated elastomer product.

Determination of free carboxylic acids and their salts, in particularcalcium and zinc stearate or palmitate can be accomplished bymeasurement using Gas Chromatography with a Flame Ionization Detector(GC-FID) according to the following procedure:

2 g of a sample of halogenated elastomer are weight out to the nearest0.0001 g, placed in a 100 mL jar and combined with

-   -   a) 25 mL hexane, 1,000 mL of an internal standard solution where        levels of free carboxylic acids are to be determined and    -   b) 25 mL hexane, 1,000 mL of an internal standard solution and 5        drops of concentrated sulfuric acid where levels of carboxylic        acid salts are to be determined.        The jar is put on a shaker for 12 hours. Then 23 ml acetone are        added and the remaining mixture evaporated to dryness at 50° C.        which takes typically 30 minutes.

Thereafter 10 ml methanol and 2 drops of concentrated sulfuric acid areadded, shaken to mix and heated for 1 hour to 50° C. to convert thecarboxylic acids into their methyl esters. Thereafter 10 ml hexane and10 ml demineralized water are added, vigourously shaken and finally thehexane layer is allowed to separate. 2 ml of the hexane solution areused for GC-FID analysis.

It is known to those skilled in the art that technical stearates such ascalcium and zinc stearate also contain fractions of other calcium andzinc carboxylic acid salts such as palmitates. However, GC-FID allows todetermine the contents of other carboxylic acids as well.

Direct measurement of carboxylic acid salts in particular stearates andpalmitates can be accomplished by FTIR as follows: A sample of rubber ispressed between two sheets of silicon release paper in a paper sampleholder and analyzed on an infrared spectrometer. Calcium stearatecarbonyl peaks are found at 1541.8 &1577.2 cm⁻¹. The peaks of heatconverted calcium stearate (a different modification of calciumstearate, see e.g. Journal of Colloid Science Volume 4, Issue 2, April1949, Pages 93-101) are found at 1562.8 and 1600.6 cm⁻¹ and are alsoincluded in the calcium stearate calculation. These peaks are ratioed tothe peak at 950 cm⁻¹ to account for thickness variations in the samples.

By comparing peak heights to those of known standards with predeterminedlevels of calcium stearate, the concentrations of calcium stearate canbe determined. The same applies to other carboxylic acid salts inparticular stearates and palmitates as well. For example, a single zincstearate carbonyl peak is found at 1539.5 cm⁻¹, for sodium stearate asingle carbonyl peak is found at 1558.5 cm⁻¹.

Contents of mono- or multivalent metal ions, in particular multivalentmetal ions such as calcium and zinc contents can generally be determinedand were determined if not mentioned otherwise by Inductively coupledplasma atomic emission spectrometry (ICP-AES) according to EPA 6010Method C using NIST traceable calibration standards after microwavedigestion according to EPA 3052 method C.

Additionally or alternatively contents of various elements can bedetermined by X-ray fluorescence (XRF). The sample is irradiated withX-ray radiation of sufficient energy to excite the elements of interest.The elements will give off energy specific to the element type which isdetected by an appropriate detector. Comparison to standards of knownconcentration and similar matrix will give quantitation of the desiredelement. Contents of LCST compounds, in particular methyl cellulosecontents are measurable and were measured using Gel FiltrationChromatography on a Waters Alliance 2690/5 separations module equippedwith a PolySep-GFC-P4000, 300×7.8 mm aqueous GFC column and aPolySep-GFC-P4000, 35×7.8 mm guard column and a Waters 2414 DifferentialRefractometer against standards of known concentration. As gelfiltration chromatography separates based on molecular weight, it may benecessary to employ different columns than those mentioned above inorder to analyze for LCST compounds across different molecular weightranges.

The samples are for example prepared according to the followingprocedure:

2 g of a sample of halogenated elastomer are weighed to the nearest0.0001 g and dissolved in 30 ml hexanes using a shaker at low speedovernight in a closed vial. Exactly 5 ml of HPLC grade water at roomtemperature are added, the vial is recapped and shaken another 30minutes. After phase separation the aqueous phase was used for GelFiltration Chromatography and injected via a 0.45 micron syringe filter.

It is apparent to those skilled in the art that different analyticalmethods may result in slightly different results. However, at least tothe extent above methods are concerned, the results were found to beconsistent within their specific and inherent limits of error.

Preferred halogenated elastomers are those already described in theprocess section above and include halogenated elastomers comprisingrepeating units derived from at least one isoolefin and at least onemultiolefin whereby the repeating units derived from the multiolefin isat least partially halogenated.

Examples of suitable isoolefins include isoolefin monomers having from 4to 16 carbon atoms, preferably 4 to 7 carbon atoms, such as isobutene,2-methyl-1-butene, 3-methyl-1-butene, 2-methyl-2-butene. A preferredisolefin is isobutene.

Examples of suitable multiolefins include isoprene, butadiene,2-methylbutadiene, 2,4-dimethylbutadiene, piperyline,3-methyl-1,3-pentadiene, 2,4-hexadiene, 2-neopentylbutadiene,2-methyl-1,5-hexadiene, 2,5-dimethyl-2,4-hexadiene,2-methyl-1,4-pentadiene, 4-butyl-1,3-pentadiene,2,3-dimethyl-1,3-pentadiene, 2,3-dibutyl-1,3-pentadiene,2-ethyl-1,3-pentadiene, 2-ethyl-1,3-butadiene, 2-methyl-1,6-heptadiene,cyclopentadiene, methylcyclopentadiene, cyclohexadiene and1-vinyl-cyclohexadiene.

Preferred multiolefins are isoprene and butadiene. Isoprene isparticularly preferred.

The halogenated elastomers may or may not further comprise repeatingunits derived from further olefins which are neither isoolefins normultiolefins.

Examples of such suitable olefins include β-pinene, styrene,divinylbenzene, diisopropenylbenzene o-, m- and p-alkylstyrenes such aso-, m- and p-methyl-styrene.

The multiolefin content of halogenated elastomers produced according tothe invention is typically 0.1 mol-% or more, preferably of from 0.1mol-% to 15 mol-%, in another embodiment 0.5 mol-% or more, preferablyof from 0.5 mol-% to 10 mol-%, in another embodiment 0.7 mol-% or more,preferably of from 0.7 to 8.5 mol-% in particular of from 0.8 to 1.5 orfrom 1.5 to 2.5 mol-% or of from 2.5 to 4.5 mol-% or from 4.5 to 8.5mol-%, particularly where isobutene and isoprene are employed.

The halogen level may for example of from 0.1 to 5 wt.-%, preferably offrom 0.5 to 3.0 wt.-% with respect to the halogenated elastomer.

The halogenated elastomer may be a brominated elastomer or a chlorinatedelastomer.

The term “multiolefin content” denotes the molar amount of repeatingunits derived from multiolefins with respect to all repeating units ofthe halogenated elastomer. The halogenated elastomer particles obtainedaccording to the invention typically appear as a light and crumblymaterial.

In one embodiment the halogenated elastomer particles exhibit a bulkdensity of from 0.05 kg/l to 0.800 kg/l.

In a further step D) the halogenated elastomer particles obtained instep C) are subjected to a shaping process such as baling.

The invention therefore encompasses a shaped article in particular abale obtainable by shaping, in particular baling the halogenatedelastomer particles or the halogenated elastomer products. Shaping canbe performed using any standard equipment known to those skilled in theart for such purposes. Baling can e.g. performed with conventional,commercially available balers. Shaped articles are also encompassed bythe term halogenated elastomer product.

In one embodiment the shaped article in particular the bale exhibits adensity of from 0.700 kg/l to 0.850 kg/l.

In another embodiment the shaped article is cuboid and has a weight offrom 10 to 50 kg, preferably 25 to 40 kg.

It is apparent for those skilled in the art, that the density of theshaped article in particular the bale is higher than the bulk density ofthe halogenated elastomer particles employed for its production.

Blends

The halogenated elastomer particles, reshaped polymer particles andshaped articles made from halogenated elastomer particles or thehalogenated elastomer products are hereinafter referred to as thehalogenated elastomers according to the invention. One or more of thehalogenated elastomers according to the invention may be blended eitherwith each other or additionally or alternatively with at least onesecondary rubber being different from the halogenated elastomer formingthe halogenated elastomer particles, which is preferably selected fromthe group consisting of natural rubber (NR), epoxidized natural rubber(ENR), polyisoprene rubber, poly(styrene-co-butadiene) rubber (SBR),chloroprene rubber (CR), polybutadiene rubber (BR), perfluorohalogenatedelastomer (FFKM/FFPM), ethylene vinylacetate (EVA) rubber, ethyleneacrylate rubber, polysulphide rubber (TR), poly(isoprene-co-butadiene)rubber (IBR), styrene-isoprene-butadiene rubber (SIBR),ethylene-propylene rubber (EPR), ethylene-propylene-diene M-class rubber(EPDM), polyphenylensulfide, nitrile-butadiene rubber (NBR),hydrogenated nitrile-butadiene rubber (HNBR), propylene oxide polymers,star-branched butyl rubber and halogenated star-branched butyl rubber,butyl rubbers which are not subject of the present invention i.e. havingi.a. different levels of multivalent metal ions or purity grages,star-branched polyisobutylene rubber, star-branched brominated butyl(polyisobutylene/isoprene halogenated elastomer) rubber;poly(isobutylene-co-p-methylstyrene) and halogenatedpoly(isobutylene-co-p-methylstyrene),poly(isobutylene-co-isoprene-co-styrene),poly(isobutylene-co-isoprene-co-alpha-methylstyrene), halogenatedpoly(isobutylene-co-isoprene-co-a-methylstyrene).

One or more of the halogenated elastomers according to the invention orthe blends with secondary rubbers described above may be further blendedadditionally or alternatively for example simultaneously or separatelywith at least one thermoplastic polymer, which is preferably selectedfrom the group consisting of polyurethane (PU), polyacrylic esters (ACM,PMMA), thermoplastic polyester urethane (AU), thermoplastic polyetherurethane (EU), perfluoroalkoxyalkane (PFA), polytetrafluoroethylene(PTFE), and polytetrafluoroethylene (PTFE).

One or more of the halogenated elastomers according to the invention orthe blends with secondary rubbers and/or thermoplastic polymersdescribed above may be compounded with one or more fillers. The fillersmay be non-mineral fillers, mineral fillers or mixtures thereof.Non-mineral fillers are preferred in some embodiments and include, forexample, carbon blacks, rubber gels and mixtures thereof. Suitablecarbon blacks are preferably prepared by lamp black, furnace black orgas black processes. Carbon blacks preferably have BET specific surfaceareas of 20 to 200 m²/g. Some specific examples of carbon blacks areSAF, ISAF, HAF, FEF and GPF carbon blacks. Rubber gels are preferablythose based on polybutadiene, butadiene/styrene halogenated elastomers,butadiene/acrylonitrile halogenated elastomers or polychloroprene.

Suitable mineral fillers comprise, for example, silica, silicates, clay,bentonite, vermiculite, nontronite, beidelite, volkonskoite, hectorite,saponite, laponite, sauconite, magadiite, kenyaite, ledikite, gypsum,alumina, talc, glass, metal oxides (e.g. titanium dioxide, zinc oxide,magnesium oxide, aluminum oxide), metal carbonates (e.g. magnesiumcarbonate, calcium carbonate, zinc carbonate), metal hydroxides (e.g.aluminum hydroxide, magnesium hydroxide) or mixtures thereof.

Dried amorphous silica particles suitable for use as mineral fillers mayhave a mean agglomerate particle size in the range of from 1 to 100microns, or 10 to 50 microns, or 10 to 25 microns. In one embodiment,less than 10 percent by volume of the agglomerate particles may be below5 microns. In one embodiment, less than 10 percent by volume of theagglomerate particles may be over 50 microns in size. Suitable amorphousdried silica may have, for example, a BET surface area, measured inaccordance with DIN (Deutsche Industrie Norm) 66131, of between 50 and450 square meters per gram. DBP absorption, as measured in accordancewith DIN 53601, may be between 150 and 400 grams per 100 grams ofsilica. A drying loss, as measured according to DIN ISO 787/11, may befrom 0 to 10 percent by weight. Suitable silica fillers are commerciallysold under the names HiSil™ 210, HiSil™ 233 and HiSil™ 243 availablefrom PPG Industries Inc. Also suitable are Vulkasil™ S and Vulkasil™ N,commercially available from Bayer AG.

High aspect ratio fillers useful in the present invention may includeclays, talcs, micas, etc. with an aspect ratio of at least 1:3. Thefillers may include acircular or nonisometric materials with a platy orneedle-like structure. The aspect ratio is defined as the ratio of meandiameter of a circle of the same area as the face of the plate to themean thickness of the plate. The aspect ratio for needle and fibershaped fillers is the ratio of length to diameter. The high aspect ratiofillers may have an aspect ratio of at least 1:5, or at least 1:7, or ina range of 1:7 to 1:200. High aspect ratio fillers may have, forexample, a mean particle size in the range of from 0.001 to 100 microns,or 0.005 to 50 microns, or 0.01 to 10 microns. Suitable high aspectratio fillers may have a BET surface area, measured in accordance withDIN (Deutsche Industrie Norm) 66131, of between 5 and 200 square metersper gram. The high aspect ratio filler may comprise a nanoclay, such as,for example, an organically modified nanoclay. Examples of nanoclaysinclude natural powdered smectite clays (e.g. sodium or calciummontmorillonite) or synthetic clays (e.g. hydrotalcite or laponite). Inone embodiment, the high aspect filler may include organically modifiedmontmorillonite nanoclays. The clays may be modified by substitution ofthe transition metal for an onium ion, as is known in the art, toprovide surfactant functionality to the clay that aids in the dispersionof the clay within the generally hydrophobic polymer environment. In oneembodiment, onium ions are phosphorus based (e.g. phosphonium ions) ornitrogen based (e.g. ammonium ions) and contain functional groups havingfrom 2 to 20 carbon atoms. The clays may be provided, for example, innanometer scale particle sizes, such as, less than 25 μm by volume. Theparticle size may be in a range of from 1 to 50 μm, or 1 to 30 μm, or 2to 20 μm. In addition to silica, the nanoclays may also contain somefraction of alumina. For example, the nanoclays may contain from 0.1 to10 Wt.-% alumina, or 0.5 to 5 Wt.-% alumina, or 1 to 3 Wt.-% alumina.Examples of commercially available organically modified nanoclays ashigh aspect ratio mineral fillers include, for example, those sold underthe trade name Cloisite® clays 10A, 20A, 6A, 15A, 30B, or 25A.

One or more of the halogenated elastomers according to the invention orthe blends with secondary rubbers and/or thermoplastic polymers or thecompounds described above are hereinafter collectively referred to aspolymer products and may further contain other ingredients such ascuring agents, reaction accelerators, vulcanizing accelerators,vulcanizing acceleration auxiliaries, antioxidants, foaming agents,anti-aging agents, heat stabilizers, light stabilizers, ozonestabilizers, processing aids, plasticizers, tackifiers, blowing agents,dyestuffs, pigments, waxes, extenders, organic acids, inhibitors, metaloxides, and activators such as triethanolamine, polyethylene glycol,hexanetriol, etc., which are known to the rubber industry. Theseingredients are used in conventional amounts that depend, inter alia, onthe intended use.

The polymer products may further contain a curing system which allowsthem to be cured.

The choice of curing system suitable for use is not particularlyrestricted and is within the purview of a person skilled in the art. Incertain embodiments, the curing system may be sulphur-based,peroxide-based, resin-based or ultraviolet (UV) light-based.sulfur-based curing system may comprise: (i) at least one metal oxidewhich is optional, (ii) elemental sulfur and (iii) at least onesulfur-based accelerator. The use of metal oxides as a component in thesulphur curing system is well known in the art and preferred.

A suitable metal oxide is zinc oxide, which may be used in the amount offrom about 1 to about 10 phr. In another embodiment, the zinc oxide maybe used in an amount of from about 2 to about 5 phr.

Elemental sulfur, is typically used in amounts of from about 0.2 toabout 2 phr.

Suitable sulfur-based accelerators may be used in amounts of from about0.5 to about 3 phr.

Non-limiting examples of useful sulfur-based accelerators includethiuram sulfides (e.g. tetramethyl thiuram disulfide (TMTD)),thiocarbamates (e.g. zinc dimethyl dithiocarbamate (ZDMC), zinc dibutyldithiocarbamate (ZDBC), zinc dibenzyldithiocarbamate (ZBEC) and thiazylor benzothiazyl compounds (e.g. 4-morpholinyl-2-benzothizyl disulfide(Morfax), mercaptobenzothiazol (MBT) and mercaptobenzothiazyl disulfide(MBTS)). A sulphur based accelerator of particular note ismercaptobenzothiazyl disulfide.

Depending on the specific nature an in particular the level ofunsaturation of the halogenated elastomers according to the inventionperoxide based curing systems may also be suitable. A peroxide-basedcuring system may comprises a peroxide curing agent, for example,dicumyl peroxide, di-tert-butyl peroxide, benzoyl peroxide,2,2′-bis(tert.-butylperoxy diisopropylbenzene (Vulcup® 40KE), benzoylperoxide, 2,5-dimethyl-2,5-di(tert-butylperoxy)-hexyne-3,2,5-dimethyl-2,5-di(benzoylperoxy)hexane,(2,5-bis(tert-butylperoxy)-2,5-dimethyl hexane and the like. One suchperoxide curing agent comprises dicumyl peroxide and is commerciallyavailable under the name DiCup 40C. Peroxide curing agents may be usedin an amount of about 0.2-7 phr, or about 1-6 phr, or about 4 phr.Peroxide curing co-agents may also be used. Suitable peroxide curingco-agents include, for example, triallyl isocyanurate (TAIC)commercially available under the name DIAK 7 from DuPont,N,N′-m-phenylene dimaleimide known as HVA-2 from DuPont or Dow),triallyl cyanurate (TAC) or liquid polybutadiene known as Ricon D 153(supplied by Ricon Resins). Peroxide curing co-agents may be used inamounts equivalent to those of the peroxide curing agent, or less. Thestate of peroxide cured articles is enhanced with butyl polymerscomprising increased levels of unsaturation, for example a multiolefincontent of at least 0.5 mol-%.

The polymer products may also be cured by the resin cure system and, ifrequired, an accelerator to activate the resin cure.

Suitable resins include but are not limited to phenolic resins,alkylphenolic resins, alkyled phenols, halogenated alkyl phenolic resinsand mixtures thereof.

When used for curing butyl rubber, a halogen activator is occasionallyused to effect the formation of crosslinks. Such activators includestannous chloride or halogen-containing polymers such aspolychloroprene. The resin cure system additionally typically includes ametal oxide such as zinc oxide.

Halogenated resins in which some of the hydroxyl groups of the methylolgroup are replaced with, e.g., bromine, are more reactive. With suchresins the use of additional halogen activator is not required.

Illustrative of the halogenated phenol aldehyde resins are thoseprepared by Schenectady Chemicals, Inc. and identified as resins SP 1055and SP 1056. The SP 1055 resin has a methylol content of about 9 toabout 12.5% and a bromine content of about 4%. whereas the SP 1056 resinhas a methylol content of about 7.5 to about 11% and a bromine contentof about 6%. Commercial forms of the nonhalogenated resins are availablesuch as SP-1044 with a methylol content of about 7 to about 9.5% andSP-1045 with a methylol content of about 8 to about 11%.

The selection of the various components of the resin curing system andthe required amounts are known to persons skilled in the art and dependupon the desired end use of the rubber compound. The resin cure as usedin the vulcanization of halogenated elastomers comprising unsaturation,and in particular for butyl rubber is described in detail in “RubberTechnology” Third Edition, Maurice Morton, ed., 1987, pages 13-14, 23,as well as in the patent literature, see, e.g., U.S. Pat. Nos. 3,287,440and 4,059,651.

Since the aforementioned sulfur-based curing system, resin cure systemsand peroxide based curing systems are particularly useful in combinationwith the copolymers according to the invention, the invention alsoencompasses the use of such cure sulfur-based curing system, resin curesystems and peroxide based curing systems and their specific componentsas mentioned above singly and jointly for curing compounds comprisingthe copolymers according to the invention.

To the extent the polymer products disclosed above whether uncure orcured exhibit the levels of salts of multivalent metal ions, inparticular the levels of stearates and palmitates of multivalent metalions with respect to their contents of the halogenated elastomersaccording to the invention there are as such novel and consequentlyencompassed by the invention as well.

The invention further encompasses the use of the halogenated elastomersaccording to the invention to prepare the polymer products describedabove and a process for the preparation of the polymer productsdescribed above by blending or compounding the ingredients mentionedabove.

Such ingredients may be compounded together using conventionalcompounding techniques. Suitable compounding techniques include, forexample, mixing the ingredients together using, for example, an internalmixer (e.g. a Banbury mixer), a miniature internal mixer (e.g. a Haakeor Brabender mixer) or a two roll mill mixer. An extruder also providesgood mixing, and permits shorter mixing times. It is possible to carryout the mixing in two or more stages, and the mixing can be done indifferent apparatuses, for example one stage in an internal mixer andone stage in an extruder. For further information on compoundingtechniques, see Encyclopedia of Polymer Science and Engineering, Vol. 4,p. 66 et seq. (Compounding). Other techniques, as known to those ofskill in the art, are further suitable for compounding.

It was surprisingly found that the halogenated elastomers according tothe invention due to their low stearate concentration allow much bettercuring, in particular when resin cured as will be shown in theexperimental part.

Applications

The polymer products according to the invention are highly useful inwide variety of applications. The low degree of permeability to gases,the unsaturation sites which may serve as crosslinking, curing or postpolymerization modification site as well as their low degree ofdisturbing additives accounts for the largest uses of these rubbers.

Therefore, the invention also encompasses the use of the polymerproducts according to the invention for innerliners, bladders, tubes,air cushions, pneumatic springs, air bellows, accumulator bags, hoses,conveyor belts and pharmaceutical closures. The invention furtherencompasses the aforementioned products comprising the polymer productsaccording to the invention whether cured or/uncured.

The polymer products further exhibit high damping and have uniquelybroad damping and shock absorption ranges in both temperature andfrequency.

Therefore, the invention also encompasses the use of the polymerproducts according to the invention in automobile suspension bumpers,auto exhaust hangers, body mounts and shoe soles.

The polymer products of the instant invention are also useful in tiresidewalls and tread compounds. In sidewalls, the polymer characteristicsimpart good ozone resistance, crack cut growth, and appearance.

The polymer products may be shaped into a desired article prior tocuring. Articles comprising the cured polymer products include, forexample, belts, hoses, shoe soles, gaskets, o-rings, wires/cables,membranes, rollers, bladders (e.g. curing bladders), inner liners oftires, tire treads, shock absorbers, machinery mountings, balloons,balls, golf balls, protective clothing, medical tubing, storage tanklinings, electrical insulation, bearings, pharmaceutical stoppers,adhesives, a container, such as a bottle, tote, storage tank, etc.; acontainer closure or lid; a seal or sealant, such as a gasket orcaulking; a material handling apparatus, such as an auger or conveyorbelt; power belts, a cooling tower; a metal working apparatus, or anyapparatus in contact with metal working fluids; an engine component,such as fuel lines, fuel filters, fuel storage tanks, gaskets, seals,etc.; a membrane, for fluid filtration or tank sealing.

Additional examples where the polymer products may be used in articlesor coatings include, but are not limited to, the following: appliances,baby products, bathroom fixtures, bathroom safety, flooring, foodstorage, garden, kitchen fixtures, kitchen products, office products,pet products, sealants and grouts, spas, water filtration and storage,equipment, food preparation surfaces and equipments, shopping carts,surface applications, storage containers, footwear, protective wear,sporting gear, carts, dental equipment, door knobs, clothing,telephones, toys, catheterized fluids in hospitals, surfaces of vesselsand pipes, coatings, food processing, biomedical devices, filters,additives, computers, ship hulls, shower walls, tubing to minimize theproblems of biofouling, pacemakers, implants, wound dressing, medicaltextiles, ice machines, water coolers, fruit juice dispensers, softdrink machines, piping, storage vessels, metering systems, valves,fittings, attachments, filter housings, linings, and barrier coatings.

In a preferred specific embodiment 1, the invention relates to a processfor the preparation of an aqueous slurry comprising a plurality ofelastomer particles suspended therein, the process comprising at leastthe step of;

A*) contacting an organic medium comprisingi) at least one elastomer andii) an organic diluentwith an aqueous medium comprising at least one LCST compound having acloud point of 0 to 100° C., preferably 5 to 100° C., more preferably 15to 80 and even more preferably 20 to 70° C. and removing at leastpartially the organic diluent to obtain the aqueous slurry comprisingthe elastomer particles, whereby the elastomers are halogenated butylrubbers.

1. In a specific embodiment 2 according to specific embodiment 1 theorganic medium comprising at least a halogenated butyl rubber and anorganic diluent is obtained from a polymerization reaction or apost-polymerization.

2. In a specific embodiment 3 according to specific embodiment 1 or 2the organic medium is obtained from a polymerization reaction andsubsequent halogenation and further contains residual monomers of thepolymerization reaction.

In a specific embodiment 4 according to one of specific embodiments 1 to3 the aqueous medium contains of from 0 to 5,000 ppm, preferably of from0 to 2,000 ppm, more preferably of from 10 to 1,000 ppm, even morepreferably of from 50 to 800 ppm and yet even more preferably of from100 to 600 ppm of salts of multivalent metal ions calculated on theirmetal content and with respect to the amount of polyisobutylene presentin the medium obtained according to step A)*.

In a specific embodiment 5 according to one of specific embodiments 1 to4 the aqueous medium comprises 550 ppm or less, preferably 400 ppm orless, more preferably 300 ppm or less, even more preferably 250 ppm orless and yet even more preferably 150 ppm or less and in another yeteven more preferred embodiment 100 ppm or less of carboxylic acid saltsof multivalent metal ions calculated on their metal content and withrespect to the amount of polyisobutylene present in the medium obtainedaccording to step b).

In a specific embodiment 6 according to specific embodiments 4 or 5 thesalts of multivalent metal ions are calcium stearate and/or zincstearate and/or calcium palmitate and/or zinc palmitate.

In a specific embodiment 7 according to specific embodiment 6 thecarboxylic acid salts of multivalent metal ions are calcium stearateand/or zinc stearate and/or calcium palmitate and/or zinc palmitate.

In a specific embodiment 8 according to one of specific embodiments 1 to7 the organic medium comprising at least one elastomer and an organicdiluent is obtained from a polymerization reaction comprising at leastthe steps of:

-   -   a) providing a reaction medium comprising an organic diluent,        and at least two monomers whereby at least one monomer is an        isoolefin and at least one monomer is a multiolefin;    -   b) polymerizing the monomers within the reaction medium in the        presence of an initiator system to form an organic medium        comprising the copolymer, the organic diluent and optionally        residual monomers.    -   c) halogenation

In a specific embodiment 9 according to one of specific embodiments 1 to8 step A*) is carried out batchwise or continuously, preferablycontinuously.

In a specific embodiment 10 according to one of specific embodiments 1to 9 the temperature in step A*) is from 10 to 100° C., preferably from50 to 100° C., more preferably from 60 to 95° C. and even morepreferably from 75 to 95° C.

In a specific embodiment 11 according to one of specific embodiments 1to 10 the at least one LCST compound is selected from the groupconsisting of: poly(N-isopropylacrylamide),poly(N-isopropylacrylamide-co-N, N-dimethylacrylamide,

poly(N-isopropylacrylamide)-alt-2-hydroxyethylmethacrylate,poly(N-vinylcaprolactam), poly(N, N-diethylacrylamide),poly[2-(dimethylamino)ethyl methacrylate], poly(2-oxazoline)glyelastomers, Poly(3-ethyl-N-vinyl-2-pyrrolidone), hydroxylbutylchitosan, polyoxyethylene (20) sorbitan monostearate, polyoxyethylene(20) sorbitan monolaurate, polyoxyethylene (20) sorbitan monooleate,methyl cellulose, hydroxypropyl cellulose, hydroxyethyl methylcellulose,hydroxypropyl methylcellulose, polyethylene glycol) methacrylates with 2to 6 ethylene glycol units, polyethyleneglycol-co-polypropylene glycols,preferably those with 2 to 6 ethylene glycol units and 2 to 6polypropylene units, compounds of formula (I)

HO—[—CH₂—CH₂—O]_(x)—[—CH(CH₃)—CH₂—O]_(y)—[—CH₂—CH₂—O]_(z)—H  (I)

with y=3 to 10 and x and z=1 to 8, whereby y+x+z is from 5 to 18,polyethyleneglycol-co-polypropylene glycol, preferably those with 2 to 8ethylene glycol units and 2 to 8 polypropylene units, ethoxylatediso-C₁₃H₂₇-alcohols, preferably with an ethoxylation degree of 4 to 8,polyethylene glycol with 4 to 50, preferably 4 to 20 ethyleneglycolunits, polypropylene glycol with 4 to 30, preferably 4 to 15propyleneglycol units, polyethylene glycol monomethyl, dimethyl,monoethyl and diethyl ether with 4 to 50, preferably 4 to 20ethyleneglycol units, polypropylene glycol monomethyl, dimethyl,monoethyl and diethyl ether with 4 to 50, preferably 4 to 20propyleneglycol units, whereby methyl cellulose, hydroxypropylcellulose, hydroxyethyl methylcellulose and hydroxypropylmethylcellulose are preferred.

In a specific embodiment 12 according to one of specific embodiments 1to lithe process comprises a further step wherein the elastomerparticles contained in the aqueous slurry obtained according to step A*)are separated to obtain isolated elastomer particles.

In a specific embodiment 13 according to one of specific embodiments 1to 11 the process comprises a further step wherein the elastomerparticles contained in the aqueous slurry obtained according to step A*)are separated to obtain isolated elastomer particles and further stepwherein the (isolated) elastomer particles are dried, preferably to aresidual content of volatiles of 7,000 or less, preferably 5,000 orless, even more preferably 4,000 or less and in on other embodiment2,000 ppm or less, preferably 1,000 ppm or less.

In a specific embodiment 14 according to one of specific embodiments 1to 12 the process comprises as a further step shaping of the elastomerparticles to obtain reshaped elastomer particles such as pellets orshaped articles such as bales.

In a specific embodiment 15 the invention encompasses an aqueous slurryobtainable according to one of specific embodiments 1 to 14.

In a specific embodiment 16 the invention encompasses the use of LCSTcompounds having a cloud point of 0 to 100° C., preferably 5 to 100° C.,more preferably 15 to 80° C. and even more preferably 20 to 70° C. asdefined in specific embodiment 1 as anti-agglomerant in particular forhalogenated butyl rubber particles.

In a specific embodiment 17 the invention encompasses a method toprevent or reduce or to slow-down agglomeration of slurries comprisinghalogenated butyl rubber particles suspended in aqueous media byaddition or use of LCST compounds having a cloud point of 0 to 100° C.,preferably 5 to 100° C., more preferably 15 to 80° C. and even morepreferably 20 to 70° C. as defined in specific embodiment 1.

In a specific embodiment 18 the invention encompasses halogenated butylrubber particles having a halogenated butyl rubber content of 98.5 wt.-%or more, preferably 98.8 wt.-% or more, more preferably 99.0 wt.-% ormore even more preferably 99.2 wt.-% or more, yet even more preferably99.4 wt.-% or more and in another embodiment 99.5 wt.-% or more.

In a specific embodiment 19 according to specific embodiment 18 thehalogenated butyl rubber has a weight average molecular weight in therange of from 10 to 2,000 kg/mol, preferably in the range of from 20 to1,000 kg/mol, more preferably in the range of from 50 to 1,000 kg/mol,even more preferably in the range of from 200 to 800 kg/mol, yet morepreferably in the range of from 375 to 550 kg/mol, and most preferablyin the range of from 400 to 500 kg/mol.

In a specific embodiment 20 according to specific embodiments 18 or 19the polyisobutylene has a Mooney viscosity of at least 10 (ML 1+8 at125° C., ASTM D 1646), preferably of from 20 to 80 and even morepreferably of from 25 to 60 (ML 1+8 at 125° C., ASTM D 1646).

In a specific embodiment 21 according to one of specific embodiments 18to 20 the halogenated butyl rubber particles further comprise 0 to 0.4wt.-%, preferably 0 to 0.2 wt.-%, more preferably 0 to 0.1 wt.-% andmore preferably 0 to 0.05 wt.-% of salts of multivalent metal ions,preferably stearates and palmitates of multivalent metal ions.

In a specific embodiment 22 according to one of specific embodiments 18to 21 the halogenated butyl rubber particles further comprise 1 ppm to18,000 ppm, preferably 1 ppm to 5,000 ppm, more preferably from 1 ppm to2,000 ppm and in a more preferred embodiment from 5 to 1,000 ppm or from5 to 500 ppm of at least one LCST compound.

In a specific embodiment 23 the invention encompasses a shaped article,in particular a pellet or bale obtainable by shaping halogenated butylrubber particles according to specific embodiments 18 to 22.

In a specific embodiment 24 the invention encompasses blends orcompounds obtainable by blending or compounding the halogenated butylrubber particles according to specific embodiments 18 to 22 or theshaped articles of specific embodiment 23.

In a specific embodiment 25 the invention encompasses the use of thehalogenated butyl rubber particles according to specific embodiments 18to 22 or the shaped articles of specific embodiment 23 or the blends orcompounds according to specific embodiment 24 for innerliners, bladders,tubes, air cushions, pneumatic springs, air bellows, accumulator bags,hoses, conveyor belts and pharmaceutical closures, automobile suspensionbumpers, auto exhaust hangers, body mounts, shoe soles, tire sidewallsand tread compounds, belts, hoses, shoe soles, gaskets, o-rings,wires/cables, membranes, rollers, bladders (e.g. curing bladders), innerliners of tires, tire treads, shock absorbers, machinery mountings,balloons, balls, golf balls, protective clothing, medical tubing,storage tank linings, electrical insulation, bearings, pharmaceuticalstoppers, adhesives, a container, such as a bottle, tote, storage tank,a container closure or lid; a seal or sealant, such as a gasket orcaulking; a material handling apparatus, such as an auger or conveyorbelt; a cooling tower; a metal working apparatus, or any apparatus incontact with metal working fluids; an engine component, such as fuellines, fuel filters, fuel storage tanks, gaskets, seals, etc.; amembrane, for fluid filtration or tank sealing.

The invention also encompasses specific embodiments which arecombinations of the 25 specific embodiments listed hereinabove withgeneral embodiments, including any level of preferred embodiments,ranges parameters as disclosed above.

The invention is hereinafter further explained by the examples withoutbeing limited thereto.

EXPERIMENTAL SECTION General Method for Examples 1 to 18

A cement was prepared by dissolving different halogenated rubbers asindicated in TABLE 1 below in hexanes (˜80% n-hexane, remainder beingbranched hexane isomers). The calcium stearate content of thehalogenated rubber used in the cement was in all cases <0.1 wt %, andthe total concentration of halogenated rubber in the cement was 10 wt %.The amount of cement indicated in TABLE 1 was pumped using a peristalticpump at a flow rate of approximately 50 mL per minute into an agitatedvessel containing 2 l of deionized water at a temperature of around 65°C. at atmospheric pressure.

Low pressure steam (approximately 5-10 psi) was injected into the cementstream at the point of cement entry into the water vessel. When anappropriate level or type of anti-agglomerant is used in the watervessel, this process results in the production of rubber crumb. When ananti-agglomerant is omitted, no crumb is formed.

Abbreviations Used in TABLE 1 Antiagglomerants:

-   MC-1: methyl cellulose type M 0512 purchased by Sigma Aldrich having    a viscosity of 4000 cp at 2 wt.-% in water and 20° C. and a    molecular weight of approximately 88,000, a degree of substitution    of from 1.5 to 1.9 and methoxy substitution of 27.5 to 31.5 wt.-%.-   MC-2: methyl cellulose type M 6385 purchased by Sigma Aldrich having    a viscosity of 25 cp at 2 wt.-% in water and 20° C. and a molecular    weight of approximately 17,000.-   MC-3: methyl cellulose type M 0262 purchased by Sigma Aldrich having    a viscosity of 400 cp at 2 wt.-% in water and 20° C. and a molecular    weight of approximately 41,000.-   MC-4: methyl cellulose type M 0387 purchased by Sigma Aldrich having    a viscosity of 1500 cp at 2 wt.-% in water and 20° C. and a    molecular weight of approximately 63,000.-   HPMC: Hydroxypropyl methyl cellulose having a viscosity 2,600-5,600    cp (2 wt.-% in water at 20° C.), H7509, Sigma-   HPC: Hydroxypropyl cellulose-   HEMC: Hydroxyethyl methyl cellulose having a viscosity 600-1500    mPas, 2 wt.-% in water (20° C.), Sigma

Calcium Stearate was used a 50 wt.-% dispersion in water all otherantiagglomerants as solution is water.

TABLE 1 results Mass Anti- Dry Amount Exp. agglom- Level** Rubber added**** No. Rubber* erant [ppm] Result*** (g) [g] 1 CIIR none 0Agglomerates 5 0.000 2 CIIR Calcium 11312 Crumb 4.42 0.100 Stearate 3CIIR Calcium 26525 Crumb 3.77 0.200 Stearate 4 CIIR MC-1 840 Crumb 5.950.063 5 CIIR MC-1 1786 Crumb 5.6 0.126 6 CIIR Calcium 4259 Some discrete5.87 0.050 Stearate particles 7 CIIR MC-1 424 Crumb 5.89 0.313 8 BIIRMC-1 1435 Crumb 6.97 1.250 9 CIIR HPC 1761 Large Crumb 5.68 1.000 10CIIR HEMC 1427 Crumb 7.01 2.000 11 CIIR Gelatin 1748 Agglomerates 5.725.000 12 CIIR Xanthan 1916 Agglomerates 5.22 5.556 gum 13 CIIR Guar gum1988 Agglomerates 5.03 5.556 14 CIIR HPMC 1996 Crumb 5.01 5.000 15 CIIRMC-2 2114 Crumb 4.73 2.000 16 CIIR MC-3 1812 Crumb 5.52 2.000 17 CIIRMC-4 1773 Crumb 5.64 2.000 18 CIIR MC-1 1859 Crumb 5.38 2.000 Rubbers*CIIR: Chlorobutylrubber (chlorinated isoprene-isobutylene rubber) havinga chlorine content of 1.25 wt % and a mooney viscosity (ML (1 + 8) 125°C.) of 38 BIIR: Bromobutylrubber (brominated isoprene-isobutylenerubber) having a bromine content of 1.80 wt % and a mooney viscosity (ML(1 + 8) 125° C.) of 32 Level** Level of antiagglomerant in the aqeuosphase calculated on the amount of rubber employed Result*** Formation of“Agglomerates” indicates no sufficient amount or type of agglomerant toform aqueous suspensions of discrete rubber particles Formation of“crumb” indicates sufficient amount or type of agglomerant to formaqueous suspensions of discrete rubber particles Amount added ****Indicates the total amount of antiagglomerant employed in the aqeousphase.

The methods employed to determine the cloud points were:

-   -   1) DIN EN 1890 of September 2006, method A    -   2) DIN EN 1890 of September 2006, method C    -   3) DIN EN 1890 of September 2006, method E    -   4) DIN EN 1890 of September 2006, method A wherein the amount of        compound tested is reduced from 1 g per 100 ml of distilled        water to 0.05 g per 100 ml of distilled water.    -   5) DIN EN 1890 of September 2006, method A wherein the amount of        compound tested is reduced from 1 g per 100 ml of distilled        water to 0.2 g per 100 ml of distilled water.

For all LCST compounds the measurements were repeated twice to confirmreproducibility.

TABLE 2 LCST compound Cloud point [° C.] Method MC-1 39.0 5) MC-2 39.95) MC-3 42.1 5) MC-4 38.9 5) HPC 48.8 1) HEMC 80.8 5) HPMC 48.1 5)

Results

The experiments 1, 2, 3 and 6 clearly demonstrate that under the generalconditions employed calcium stearate requires very high levels to formcrumb, whereas the LCST compounds according to the invention allow crumbformation at moderate to low levels (see examples 4, 5, 7-10 and 14 to18). Non-LCST surfactants, dispersants and anti-agglomerants failed at acomparable level (see examples 11 to 13).

Bromobutyl Cure Examples 19 and 20

Low calcium stearate fast cure with bromobutyl:

In order to demonstrate the advantages of removing calcium stearate, abromobutyl sample was prepared with a mooney viscosity of 33 and abromine content of 1.8 wt % was prepared with ˜0.5 wt % calcium stearateand 0.011 wt % methyl cellulose (example 19). A commercially availablebromobutyl sample with a mooney viscosity of 33 and a bromine content of1.8 wt % with a calcium stearate content of 2.5 wt % and no methylcellulose was also obtained (example 20).

These two halogenated elastomers were compounded using a zinc oxideformulation given in TABLE 3. In each case, upon curing, the halogenatedelastomer with reduced calcium stearate showed a superior cure rate inthe same curing time/temperature.

TABLE 3 ZnO cure formulation (phr) Bromobutyl (with or without CaSt2)100 CARBON BLACK IRB#7 40 ZnO 5 STEARIC ACID (TRIPLE PRESSED) 1 Totalphr 146

Compounding Procedure

Ingredients used are listed in TABLE 3; units are in parts per hundredrubber (phr). The rubber was pre-milled on a two roll mill operating at30° C. using two ¾ cuts and two endwise passes. For the mixes to containmethyl cellulose, the methyl cellulose was incorporated on the mill inthis step. The butyl rubber from the mill was added to a Brabenderinternal mixer with a capacity of 75 ml equipped with Banbury rotorsoperating at 60° C. and 60 rpm. After one minute 40 phr of carbon blackIRB #7 and 1 phr of stearic acid (triple pressed) were added. A sweepwas performed at 4 minutes and the mixture was dumped at 6 minutes. ZnOwas incorporated into the rubber compound on a two-roll mill operatingat 30° C.

Curing

The t_(c) 90 and delta torques were determined according to ASTM D-5289with the use of a Moving Die Rheometer (MDR 2000E) using a frequency ofoscillation of 1.7 Hz and a 1° arc at 160° C. for 30 minutes total runtime.

TABLE 4 Compound (2) using Compound (1) using bromobutyl rubber withbromobutyl rubber ~0.5 wt % CaSt2 and with with 2.5 wt % CaSt2 0.011 wt% methyl cellulose Compound (Ex. 19) (Ex. 20) Frequency (Hz) 1.7 1.7Test Temperature (° C.) 160 160 Degree Arc (°) 1 1 Test Duration (min)30 30 Torque Range (dN · m) MH (dN · m) 10.06 10.89 ML (dN · m) 3.733.98 Delta MH-ML (dN · m) 6.33 6.91 ts 1 (min) 1.96 1.25 ts 2 (min) 3.762.31 t′ 10 (min) 1.4 0.99 t′ 25 (min) 2.87 1.97 t′ 50 (min) 6.76 3.42 t′90 (min) 11.37 5.04 t′ 95 (min) 12.49 5.58 MH = maximum torque, ML =minimum torque, t′ x = time to x % of maximum torque in minutes, TS1 andTS2 are time in minutes to increase torque by 1 and 2 dNm respectively.

As evidenced by the examples the halogenated elastomer according to theinvention shows superior cure speed as compared to its analoguecontaining high levels of calcium stearate.

Examples 21a) and 21b) Continuous Preparation of Halogenated ButylRubber

Isobutylene and isoprene were combined with methyl chloride to prepare apolymerization feedstock such that the total concentration of themonomers was from approximately 10-40 wt.-%. This feedstock stream wascooled to approximately −100° C. and was fed continuously into anagitated reaction vessel, also maintained at −100° C. In the reactionvessel the feedstock was mixed with a continuously added the initiatorsystem stream, a solution of 0.05-0.5 wt.-% aluminium trichloride inmethyl chloride which is typically activated by water in a molar ratioof from 0.1:1 to 1:1 water: aluminum trichloride. Typically, thewt.-ratio of monomers in the feedstream to aluminum trichloride was heldwithin a range of 500 to 10000, preferably 500 to 5000.

The addition rates of the feedstock stream and the initiator systemstream were adjusted to provide an isobutylene isoprene halogenatedelastomer with a mooney viscosity of approximately 40 and anunsaturation level of approximately 2.4 mol-%. Within the agitatedreaction vessel the copolymer was obtained in the form of a finelydivided slurry suspended in methyl chloride.

The reaction vessel was set up and operated such that the continuousaddition of feedstock exceeds the volume of the reactor. When thisvolume was exceeded, the well mixed reaction slurry containing methylchloride, unreacted monomers and copolymer was allowed to overflow intoanother agitated vessel containing water heated from 65 to 100° C. andemployed in an amount of 12:1 by weight in relation to the copolymer.Thereby the vast majority of the diluent methylchloride was removed fromthe slurry.

If a suitable anti-agglomerant was added, this allowed for the formationof an aqueous slurry of isobutylene isoprene copolymer particles,whereby the concentration of copolymer particles in the aqueous slurryincreased as the polymerization proceeded. The final ratio of copolymerparticles to water in the aqueous slurry can vary from 15:1 to 6:1. Theaqueous slurry was then dewatered and dried using conventional means toprovide a copolymer suitable for testing and analysis.

While not added in this experiment, it is generally possible to addantioxidants and/or stabilizers such as those listed above in thedescription, e.g. Irganox® 1010 in order to increase the shelf-life ofthe non-halogenated butyl rubber.

It was demonstrated using this continuous process that it was possibleto continuously form isoprene isobutylene copolymer particles using from0.4 to 1.2 wt % calcium stearate (with respect to the copolymer) in amanner which is consistent with prior art (example 21a). It was furtherdemonstrated that comparable copolymer particles (and resulting aqueousslurry) could also be obtained by removing calcium stearate and insteadsubstituting it by any value of from 50-500 ppm with respect to thecopolymer of methyl cellulose (example 21b). Higher or lower values werenot tested in this experiment, however the adhesive behaviour of thecopolymer crumbs formed at a level of 50 ppm indicated that lower levelsof methylcellulose can be successfully employed as well.

The methyl cellulose employed had a solution viscosity at 2 wt.-%solution of 3000-5600 cps, molecular weight Mw of ˜90,000, a methoxysubstitution of 27.5-31.5 wt.-% and thus a degree of substitution ofaround 1.9.

The cloud point was 39.0° C., determined according to method 5: DIN EN1890 of September 2006, method A wherein the amount of compound testedis reduced from 1 g per 100 ml of distilled water to 0.2 g per 100 ml ofdistilled water.

Using the experimental setup, described before two products wereobtained after separating the particles from the aquous slurry anddrying. In order to add non-water soluble components such as calciumstearate in an liquid dispersion, these products contain small amountsof non-ionic surfactants. In the case of example 21a) where calciumstearate was employed the non-ionic surfactant level resulting thereofin the copolymer was <0.02 wt.-%; in the case of example 21b) where andno calcium stearate was employed the resulting non-ionic surfactantlevel in the rubber is 0.00 wt.-%.

The analytical data is set forth below:

Generally, if not mentioned otherwise, all analytical data was obtainedaccording to the procedures set forth in the description hereinabove.

Molecular weights and polydispersity were determined by gel permeationchromatography in tetrahydrofurane and reported in kg mol⁻¹. Brominecontent was measured by X-ray fluorescence, and results are reported inppm and wt. %, respectively. The content of sterically hindered phenolicanti-oxidant (Irganox™ 1010) was determined by HPLC, results arereported in wt. %. Total unsaturation and microstructure were determinedof respective signals from ¹H NMR spectra of the elastomers and arereported in mol %.

Example 21a: Base Material for Halogenation

Total unsaturation: 2.3 mol-%

Mw: 573,000 Polydispersity (Mw/Mn): 4.65

Mooney viscosity (ML 1+8 at 125° C., ASTM D 1646): 45Calcium stearate content: 0.40 wt.-% (GC-FID, FTIR)

Volatiles: 1 wt.-%

Other antiagglomerants, surfactants, emulsifiers: see above

Example 21b): Base Material for Halogenation

Total unsaturation: 2.4 mol-%

Mw: 558,400 Polydispersity (Mw/Mn): 3.91

Mooney viscosity (ML 1+8 at 125° C., ASTM D 1646): 42Calcium stearate content: below detectable limitsMethyl cellulose content: 0.005 wt.-%

Volatiles: 1.2 wt.-%

Other antiagglomerants, surfactants, emulsifiers: none

The non-halogenated butyl rubber particles obtained thereby weredewatered using a shaking screen and continuously dissolved incommercially available technical grade hexanes (min 45% n-hexane),forming a cement. This cement comprised approximately 20 wt %non-halogenated butyl rubber, 10 wt % water, and balance hexanes. Themajority of additives such as calcium stearate and methyl cellulose arecarried over into this cement and are present in the cement in theamounts described above.

This cement was added to a continuously agitated halogenation vessel,where it is mixed with chlorine gas in a ratio of approximately 27 kgchlorine per ton of nonhalogenated butyl rubber. This mixture wassubsequently neutralized by the addition of sodium hydroxide to thecement/chlorine mixture in an agitated vessel. A settling drum removedbulk water, and the now halogenated cement is continuously injected intoan agitated coagulation vessel containing water heated from 65 to 115°C. and employed in an amount of approximately 10:1 by weight in relationto the halogenated butyl rubber. This and subsequent similar strippingsteps allow for the recovery of the bulk of the hexanes used inpreparing the cement.

If a suitable anti-agglomerant was added, this allowed for the formationof an aqueous slurry of chlorinated butyl rubber particles, whereby theconcentration of chlorinated butyl rubber particles in the aqueousslurry increased as the polymerization proceeded. The final ratio ofchlorinated butyl rubber particles to water in the aqueous slurry canvary from 15:1 to 6:1. The aqueous slurry was then dewatered and driedusing conventional means to provide a chlorinated butyl rubber suitablefor testing and analysis.

It was demonstrated using this continuous process that it was possibleto continuously form chlorinated isoprene isobutylene copolymerparticles using an additional 0.7 to 1.2 wt % calcium stearate (withrespect to the chlorinated butyl rubber) in a manner which is consistentwith prior art (example 21a). It was further demonstrated thatcomparable copolymer particles (and resulting aqueous slurry) could alsobe obtained by omitting calcium stearate and instead substituting it byany value of from 150-700 ppm with respect to the chlorinated butylrubber of methyl cellulose (example 21b). Higher or lower values werenot tested in this experiment, however the adhesive behaviour of thecopolymer crumbs formed at a level of 50 ppm indicated that higher orlower levels of methylcellulose can be successfully employed as well.The methyl cellulose utilized was the same as is described in thepolymerization section above.

Halogenated Elastomer Example 21a

Total unsaturation: 2.3 mol-%

Total Chlorine: 1.24 wt %

Total allylic halide: 1.35 mol %

Mw: 559,000 Polydispersity (Mw/Mn): 3.80

Mooney viscosity (ML 1+8 at 125° C., ASTM D 1646): 39Calcium stearate content: 1.56 wt.-% (GC-FID, FTIR)

Volatiles: 0.16 wt.-% Ash: 0.28 wt % (ASTM D5667)

Other antiagglomerants, surfactants, emulsifiers: 0.04 wt.-%

Ions: (ICP-AES) Calcium: 1230 ppm

Aluminum (from catalyst): 30 ppm

Magnesium: 19 ppm

Other multivalent metal ions (Mn, Pb, Cu, Co, Cr, Ba, Fe, Zn, Sr): 19ppmMonovalent metal ions (Na, K): 238 ppm

Halogenated Elastomer Example 21b:

Total unsaturation: 2.3 mol-%

Total Chlorine: 1.27 wt %

Total allylic halide: 1.42 mol %

Mw: 544,000 Polydispersity (Mw/Mn): 3.89

Mooney viscosity (ML 1+8 at 125° C., ASTM D 1646): 37Methyl cellulose content: <0.006 wt.-%—by mass balanceCalcium stearate content (residual contamination due to continuousprocess:

0.02 wt.-% (GC-FID, FTIR) Volatiles: 0.48 wt.-% Ash: <0.01 wt % (ASTMD5667)

Other antiagglomerants, surfactants, emulsifiers: none

Ions: (ICP-AES) Calcium: 39 ppm

Aluminum (from catalyst): 35 ppm

Magnesium: 13 ppm

Other multivalent metal ions (Mn, Pb, Cu, Co, Cr, Ba, Fe, Zn, Sr): 64ppmMonovalent metal ions (Na, K): 119 ppm

Thus the halogenated butyl rubber particles according to example 21bcomprised

-   -   I) 100 parts by weight of a halogenated elastomer (phr)    -   II)<0.006 phr of a least one LCST compound and    -   III) less than 0.05 parts by weight of non-LCST compounds        selected from the group consisting of ionic or non-ionic        surfactants, emulsifiers, and antiagglomerants and    -   IV) 0.48 parts by weight of volatiles having a boiling point at        standard pressure of 200° C. or less    -   whereby these components made up more than 99.90 wt-% of the        total weight of the copolymer particles.

Further Cure Experiments:

In order to show superior performance of the halogenated elastomersaccording to the invention in various typical applications thechlorinated elastomers produced according to example 21a) and thefollowing chlorinated elastomer producible according to example 21b)with higher methylcellulose content and brominated elastomers produciblein analogy to examples 21a) and 21b) but using bromine instead ofchlorine for halogenation and using ethoxylated soy bean oil (ESBO)after neutralisation were compounded in different sulfur, zinc oxide andresin cure formulations, either unfilled or filled.

Halogenated Elastomer Example 21c: Chlorinated Butyl Rubber, Very LowCalcium Stearate Content

Total unsaturation: 2.03 mol-%

Total Chlorine: 1.18 wt %

Total allylic halide: 1.38 mol %

Mw: 542,000 Polydispersity (Mw/Mn): 4.15

Mooney viscosity (ML 1+8 at 125° C., ASTM D 1646): 37Calcium stearate content: 0.30 wt.-% (GC-FID, FTIR)Methyl cellulose content: 0.100 wt.-%

Volatiles: 0.48 wt.-% Ash: <0.01 wt % (ASTM D5667) Halogenated ElastomerExample 21d (for Comparison): Brominated Butyl Rubber, High CalciumStearate Content

Total unsaturation: 1.71 mol-%

Total Bromine: 1.74 wt %

Total allylic halide: 0.91 mol %

Mw: 513,000 Polydispersity (Mw/Mn): 3.53

Mooney viscosity (ML 1+8 at 125° C., ASTM D 1646): 34Calcium stearate content: 2.28 wt.-% (GC-FID, FTIR)ESBO content: 1.19 wt.-%

Antioxidant: 0.042 wt.-% Volatiles: <0.5 wt.-%

Other antiagglomerants, surfactants, emulsifiers: 0.04 wt.-%

Halogenated Elastomer Example 21e: Brominated Butyl Rubber, Very LowStearate Content

Total unsaturation: 1.76 mol-%

Total Bromine: 1.74 wt %

Total allylic halide: 0.91 mol %

Mw: 480,000 Polydispersity (Mw/Mn): 3.35

Mooney viscosity (ML 1+8 at 125° C., ASTM D 1646): 32Calcium stearate content: 0.3 wt.-% (GC-FID, FTIR)ESBO content: 1.06 wt.-%

Antioxidant: 0.042 wt.-% Volatiles: <0.5 wt.-%

Other antiagglomerants, surfactants, emulsifiers: none*ESBO: Epoxidized soy bean oil

Unfilled Resin Cure Formulations: Examples 22 to 25

The chlorinated elastomers according to examples 21a) (example 22) and21c) (examples 23 to 25) were compounded using the resin-cureformulation given in TABLE 5.

TABLE 5 Unfilled resin cure formulation (phr) Chlorinated elastomer 100STEARIC ACID (TRIPLE PRESSED) 1 Zinc oxide 5 Resin SP 1045**: Examples22, 23: 1.75 Example 24: 0.88 (50%) Example 25: 1.31 (75%) **SP1045:Phenolic resin based on octylphenol

Compounding Procedure:

To a Brabender internal mixer with a capacity of 75 ml equipped withBanbury rotors operating at 60° C. and 60 rpm, the chlorinated elastomerwas added. After 1 minute, steric acid was added, and after 3 minutesthe zinc oxide and resin SP 1045 were added. The mixture was dumped whentorque was stable. The chlorinated elastomer compounds were furthermixed on a two-roll mill operating at 30° C.

Curing

The t_(c)90 and delta torques were determined according to ASTM D-5289with the use of a Moving Die Rheometer (MDR 2000E) using a frequency ofoscillation of 1.7 Hz and a 1° arc at 160° C. for 60 minutes total runtime.

TABLE 6 Ex. MH-ML No. MH (dNm) ML (dNm) (dNm) t_(c)90 22 7.11 1.92 5.198.42 23 7.68 2.12 5.56 4.12 24 6.5 2.28 4.22 4.22 25 7.33 2.26 5.07 4.19

As evidenced by the examples the chlorinated elastomer according to theinvention shows a superior cure rate and cure state as compared to itsanalogue containing high levels of calcium stearate. Even with loweramounts of resin added the chlorinated elastomer according to theinvention shows a superior (75%) or at least comparable (50%) cure stateand improved cure rate.

Examples 26 to 28

The brominated elastomers according to examples 21d) (example 26) and21e) (examples 27 and 28) were compounded using the resin-cureformulation given in TABLE 7.

TABLE 7 Unfilled resin cure formulation (phr) Brominated elastomer 100STEARIC ACID (TRIPLE PRESSED) 1 Zinc oxide 5 Resin SP 1045**: Examples26, 27: 1.75 Example 28: 0.88 (50%) **SP 1045: Phenolic resin based onoctylphenol

Compounding Procedure:

To a Brabender internal mixer with a capacity of 75 ml equipped withBanbury rotors operating at 60° C. and 60 rpm, the chlorinated elastomerwas added. After 1 minute, steric acid was added, and after 3 minutesthe zinc oxide and resin SP 1045 were added. The mixture was dumped whentorque was stable. The chlorinated elastomer compounds were furthermixed on a two-roll mill operating at 30° C.

Curing

The t_(c)90 and delta torques were determined according to ASTM D-5289with the use of a Moving Die Rheometer (MDR 2000E) using a frequency ofoscillation of 1.7 Hz and a 1° arc at 160° C. for 60 minutes total runtime.

TABLE 8 Ex. MH ML MH-ML Extractables* No. (dNm) (dNm) (dNm) t_(c)90[wt.-%] 26 4.93 1.82 3.08 14.40 3.8 27 6.68 1.83 4.85 2.39 2.0 28 5.461.91 3.55 1.98 2.1 *Extraction was carried out 7 hours in a soxhletextractor using 5 g of cured compound in 400 mL of hexane

As evidenced by the examples the brominated elastomer according to theinvention shows a superior cure rate and cure state as compared to itsanalogue containing high levels of calcium stearate. Even with the halfamount of resin added the brominated elastomer according to theinvention shows a superior cure state and tremendously improved curerate. Additionally, much less extractables were found for compoundsaccording to the invention, which is desirable whenever the curedformulation come into contact with food or pharmaceuticals.

Moreover when comparing examples 26 to 28 with respect to their modulusand hardness it could be observed that with the brominated elastomeraccording to the invention even using only half the amount of resinincreased modulus is achieved.

TABLE 9 Modulus Modulus Ex. @ 100% @ 300% Hardness No. Temp. (° C.)(MPa) (MPa) Shore A 26 160 0.40 0.67 26 27 160 0.45 0.85 27 28 160 0.390.68 26

Stress strain dumbbells were cured at specified temperature (160° C. or180° C.) for t_(c)90+5 and tested using the Alpha T2000 tensile tester.The ASTM D412 Method A procedure were followed to test samples that wereunaged.

Hardness was determined according to ASTM D2240 A.

Filled Resin Cure Formulations: Examples 29 and 30

The chlorinated elastomers according to examples 21a) (example 29) and21c) (example 30) were compounded using the resin-cure formulation givenin TABLE 10.

TABLE 10 Filled resin cure formulation (phr) Chlorinated elastomer 100STEARIC ACID (TRIPLE PRESSED) 1 CARBON BLACK, N 330 VULCAN 3 50 Castoroil 5 Zinc oxide 5 Resin SP 1045 1.75

Compounding Procedure:

To a Brabender internal mixer with a capacity of 75 ml equipped withBanbury rotors operating at 60° C. and 60 rpm, the halogenated elastomerwas added. After one minute carbon black and castor oil was added, andafter three minutes the zinc oxide, stearic acid and Resin SP 1045 wereadded. The mixture was dumped when torque was stable. The halogenatedelastomer compounds were further mixed on a two-roll mill operating at30° C.

Curing

The t_(c)90 and delta torque were determined according to ASTM D-5289with the use of a Moving Die Rheometer (MDR 2000E) using a frequency ofoscillation of 1.7 Hz and a 1° arc at 160° C. for 60 minutes total runtime.

TABLE 11 Ex. MH ML MH-ML No. (dNm) (dNm) (dNm) t_(c)90 29 19.65 4.3315.32 11.04 30 21.17 4.02 17.15  6.21

As evidenced by the examples the chlorinated elastomer according to theinvention shows a superior cure rate and cure state as compared to itsanalogue containing high levels of calcium stearate.

Examples 31 and 32

The brominated elastomers according to examples 21d) (example 31) and21e) (example 32) were compounded using the resin-cure formulation givenin TABLE 12.

TABLE 12 Filled resin cure formulation (phr) Brominated elastomer 100STEARIC ACID (TRIPLE PRESSED)  1 CARBON BLACK, N 330 VULCAN 3  50 Zincoxide  5 Resin SP 1045  1.75

Compounding Procedure:

To a Brabender internal mixer with a capacity of 75 ml equipped withBanbury rotors operating at 60° C. and 60 rpm, the halogenated elastomerwas added. After one minute carbon black and castor oil was added, andafter three minutes the zinc oxide, stearic acid and Resin SP 1045 wereadded. The mixture was dumped when torque was stable. The halogenatedelastomer compounds were further mixed on a two-roll mill operating at30° C.

Curing

The t_(c)90, delta torques, ts1 and ts2 were determined according toASTM D-5289 with the use of a Moving Die Rheometer (MDR 2000E) using afrequency of oscillation of 1.7 Hz and a 1° arc at 160° C. for 60minutes total run time.

TABLE 13 Ex. MH-ML t_(s)1 t_(s)2 No. MH (dNm) ML (dNm) (dNm) (min) (min)t_(c)90 31 15.43 4.31 15.32 0.99 1.58 7.95 32 20.20 4.07 17.15 1.30 1.553.17

As evidenced by the examples the brominated elastomer according to theinvention shows a superior cure rate and cure state as compared to itsanalogue containing high levels of calcium stearate while still havingsimilar scorch safety.

Examples 33 to 36

The brominated elastomers according to examples 21d) (example 33) and21e) (examples 34 to 36) were compounded using a typical pharmaceuticalclosure formulations with varying levels of resin given in TABLE 14.

TABLE 14 Pharmaceutical closure formulation (phr) Brominated elastomer100 Polyfil 80* 85 PE Wax 2 Zinc oxide 3 Stearic acid 0.75 Resin SP 1045Examples 33, 34: 1.5 Example 35 0.75 Example 36 0.375 *Polyfil 80:Calcinated kaolin clay

Compounding Procedure:

To a Brabender internal mixer with a capacity of 75 ml equipped withBanbury rotors operating at 60° C. and 60 rpm, the copolymer was added.After one minute Polyfil 80 and PE Wax were added. After 3 minutes thezinc oxide, stearic acid and Resin SP 1045 were added. The mixture wasdumped when torque was stable. The compound was further mixed on atwo-roll mill operating at 30° C.

Curing

The t_(c)90, delta torques, were determined according to ASTM D-5289with the use of a Moving Die Rheometer (MDR 2000E) using a frequency ofoscillation of 1.7 Hz and a 1° arc at 160° C. for 60 minutes total runtime.

TABLE 15 Ex. MH ML MH-ML t_(s)1 t_(s)2 No. (dNm) (dNm) (dNm) (min) (min)t_(c)90 33 8.40 2.15 6.25 3.69 4.86 10.10 34 13.03 2.63 10.40 1.17 1.474.16 35 10.91 2.96 7.95 1.27 1.61 3.53 36 9.44 2.71 6.73 1.34 1.71 3.15

As evidenced by the examples the copolymer according to the inventionshows a superior cure rate and cure state as compared to its analoguecontaining high levels of calcium stearate in pharmaceutical closureformulations. Very good results may be obtained even using only 50% oreven only 25% of the resin.

When comparing examples 33 to 36 with respect to their modulus andhardness it is apparent that with the brominated elastomer according tothe invention even using lower amounts of resin very good physicalproperties are achieved.

TABLE 16 Modulus Modulus Ex. @ 100% @ 300% Hardness No. Temp. (° C.)(MPa) (MPa) Shore A 33 160 0.93 1.43 48 34 160 1.29 2.52 51 35 160 1.222.56 49 36 160 0.93 1.45 48

Stress strain dumbbells were cured at specified temperature (160° C. or180° C.) for t_(c)90+5 and tested using the Alpha T2000 tensile tester.The ASTM D412 Method A procedure were followed to test samples that wereunaged.

Unfilled Sulfur Cure Formulations: Examples 37 to 40

The chlorinated elastomers according to example 21a (example 37) and 21c(example 38) and the brominated elastomers according to example 21d(example 39) and 21e (example 40) were compounded using the unfilledsulphur-cure formulation given in TABLE 17.

TABLE 17 Unfilled sulfur cure formulation (phr) Halogenated elastomer100 STEARIC ACID (TRIPLE PRESSED) 1 Zinc oxide 3 Sulfur 0.5 MBTS* 1.3*MBTS: Mercaptobenzathiazolesulfide

Compounding Procedure:

To a Brabender internal mixer with a capacity of 75 ml equipped withBanbury rotors operating at 60° C. and 60 rpm, the halogenated elastomerwas added and dumped after 6 mins. To the elastomer zinc oxide, sulfur,MBTS were added and mixed on a two-roll mill operating at 30° C.

Curing

The t_(c)90 and delta torques were determined according to ASTM D-5289with the use of a Moving Die Rheometer (MDR 2000E) using a frequency ofoscillation of 1.7 Hz and a 1° arc at 166° C. for 60 minutes total runtime.

TABLE 18 Ex. MH-ML t_(s)1 t_(s)2 No. MH (dNm) ML (dNm) (dNm) (min) (min)t_(c)90 37 4.42 1.86 2.56 1.66 2.79 11.58 38 4.52 2.05 2.47 0.8 1.181.46 39 4.19 1.71 2.48 3.66 11.83 19.06 40 4.65 1.84 2.81 0.90 1.22 5.19

As evidenced by the examples the halogenated elastomers according to theinvention shows a superior cure rate and cure state as compared to theiranalogues containing high levels of calcium stearate.

Filled Sulfur Cure Formulations: Examples 41 and 42

The brominated elastomers according to example 21d (example 41) and 21e(example 42) were compounded using a filled sulphur cure formulationgiven in TABLE 19.

TABLE 19 Filled sulfur cure formulation (phr) Brominated elastomer 100STEARIC ACID (TRIPLE PRESSED) 1 Carbon Black N660 60 Zinc oxide 3 Sulfur0.5 MBTS 1.3

Compounding Procedure:

To a Brabender internal mixer with a capacity of 75 ml equipped withBanbury rotors operating at 60° C. and 60 rpm, the brominated elastomerwas added. At one minute carbon black was added and the mixture dumpedafter 6 mins. To the mixture zinc oxide, sulfur and MBTS were added andmixed on a two-roll mill operating at 30° C.

Curing

The t_(c)90 and delta torques were determined according to ASTM D-5289with the use of a Moving Die Rheometer (MDR 2000E) using a frequency ofoscillation of 1.7 Hz and a 1° arc at 166° C. for 60 minutes total runtime.

TABLE 20 MH ML MH-ML t_(s)1 t_(s)2 Ex. No. (dNm) (dNm) (dNm) (min) (min)t_(c)90 41 15.28 3.78 11.5 1.07 1.72 6.24 42 15.68 3.78 11.9 1.29 1.595.78

As evidenced by the examples the brominated elastomer according to theinvention shows a superior cure rate and cure state as compared to itsanalogue containing high levels of calcium stearate.

Examples 43 to 45

The brominated elastomers according to example 21d (example 43) and 21e(examples 44 and 45) were compounded using a typical pharmaceuticalclosure formulations with varying levels of resin given in TABLE 21.

TABLE 21 Pharmaceutical closure formulation (phr) Brominated elastomer100 Polyfil 80* 80 PE Wax 2 Zinc oxide Examples 43, 44 3 Example 45 1.95Sulfur Examples 43, 44: 0.5 Example 45 0.375 *Polyfil 80: Calcinatedkaolin clay

Compounding Procedure:

To a Brabender internal mixer with a capacity of 75 ml equipped withBanbury rotors operating at 60° C. and 60 rpm, the copolymer was added.After one minute Polyfil 80 and PE Wax were added. The mixture wasdumped after 6 minutes. To the resulting mixture zinc oxide and sulfurwere added and further mixed on a two-roll mill operating at 30° C.

Curing

The t_(c)90, delta torques, were determined according to ASTM D-5289with the use of a Moving Die Rheometer (MDR 2000E) using a frequency ofoscillation of 1.7 Hz and a 1° arc at 160° C. for 30 minutes total runtime.

TABLE 22 Ex. MH ML MH-ML t_(s)1 t_(s)2 No. (dNm) (dNm) (dNm) (min) (min)t_(c)90 43 6.43 2.16 4.27 6.55 7.71 10.95 44 8.30 2.83 5.47 2.21 2.805.09 45 7.69 2.81 4.88 2.38 3.02 4.97

As evidenced by the examples the brominated elastomer according to theinvention shows a superior cure rate and cure state as compared to itsanalogue containing high levels of calcium stearate in pharmaceuticalclosure formulations. Very good results may be obtained even using areduced amount of curing agents.

When comparing examples 43 to 45 with respect to their modulus andhardness it is apparent that with the brominated elastomer according tothe invention even using lower amounts of curing agents very goodphysical properties are achieved.

TABLE 23 Modulus Modulus Ex. @ 100% @ 300% Hardness No. Temp. (° C.)(MPa) (MPa) Shore A 43 160 0.75 1.19 46 44 160 0.94 2.01 47 45 160 0.911.99 46

Stress strain dumbbells were cured at specified temperature (160° C.)for t_(c)90+5 and tested using the Alpha T2000 tensile tester. The ASTMD412 Method A procedure were followed to test samples that were unaged.

Hardness was determined according to ASTM D2240 A.

Unfilled Zinc Oxide Cure Formulations: Examples 46 to 49

The chlorinated elastomers according to example 21a (example 46) and 21c(example 47) and the brominated elastomers according to example 21d(example 48) and 21e (example 49) were compounded using the unfilledsulphur-cure formulation given in TABLE 24.

TABLE 24 Unfilled zinc oxide cure formulation (phr) Halogenatedelastomer 100 STEARIC ACID (TRIPLE PRESSED) 1 Zinc oxide 3

Compounding Procedure:

To a Brabender internal mixer with a capacity of 75 ml equipped withBanbury rotors operating at 60° C. and 60 rpm, the halogenated elastomerwas added. The stearic acid and zinc oxider were added after 3 minutes,and dumped after 6 mins. The compound was further mixed on a two-rollmill operating at 30° C.

Curing

The t_(c)90 and delta torques were determined according to ASTM D-5289with the use of a Moving Die Rheometer (MDR 2000E) using a frequency ofoscillation of 1.7 Hz and a 1° arc at 160° C. for 60 minutes total runtime.

TABLE 25 Ex. MH-ML t_(s)1 t_(s)2 No. MH (dNm) ML (dNm) (dNm) (min) (min)t_(c)90 46 5.22 2.03 3.19 5.36 7.26 10.89 47 5.04 2.16 2.88 1.12 2.244.89 48 3.91 1.89 2.02 16.96 27.58 21.63 49 5.03 1.89 3.14 1.16 1.331.71

As evidenced by the examples the halogenated elastomers according to theinvention shows a superior cure rate and the brominated elastomer alsosuperior cure state as compared to their analogues containing highlevels of calcium stearate.

Filled Zinc Oxide Formulations: Examples 50 to 53

The chlorinated elastomers according to example 21a (example 50) and 21c(example 51) and the brominated elastomers according to example 21d(example 52) and 21e (example 53) were compounded using the unfilledsulphur-cure formulation given in TABLE 26.

TABLE 26 Filled sulfur cure formulation (phr) Brominated elastomer 100STEARIC ACID (TRIPLE PRESSED) 1 Carbon Black IRB#7 40 Zinc oxide 5

Compounding Procedure:

To a Brabender internal mixer with a capacity of 75 ml equipped withBanbury rotors operating at 60° C. and 60 rpm, the brominated elastomerwas added. At one minute carbon black was added and the mixture dumpedafter 6 mins. To the mixture zinc oxide and stearic acid were added andmixed on a two-roll mill operating at 30° C.

Curing

The t_(c)90 and delta torques were determined according to ASTM D-5289with the use of a Moving Die Rheometer (MDR 2000E) using a frequency ofoscillation of 1.7 Hz and a 1° arc at 166° C. for 60 minutes total runtime.

TABLE 27 Ex. MH-ML t_(s)1 t_(s)2 No. MH (dNm) ML (dNm) (dNm) (min) (min)t_(c)90 50 13.97 4.77 9.2 1.13 1.85 9.55 51 15.52 4.26 11.26 0.86 0.989.11 52 11.57 4.59 6.98 1.73 3.10 8.45 53 13.09 4.25 8.84 1.75 2.11 3.38

As evidenced by the examples the halogenated elastomer according to theinvention show a superior cure rate and cure state as compared to theiranalogues containing high levels of calcium stearate.

Examples 54 to 56

The brominated elastomers according to according to example 21d (example54) and 21e (examples 55 and 56) were compounded using a typicalpharmaceutical closure formulations with varying levels of resin givenin TABLE 28.

TABLE 28 Pharmaceutical closure formulation (phr) Brominated elastomer100 PE Wax 5 Calcinated clay 80 Zinc oxide Examples 54, 55 3 Example 561.50 ZBEC* Examples 54, 55: 1.5 Example 56 0.75 *ZBEC: Zincdibenzylthithiocarbamate

Compounding Procedure:

To a Brabender internal mixer with a capacity of 75 ml equipped withBanbury rotors operating at 60° C. and 60 rpm, the copolymer was added.After one minute calcinated clay and PE Wax was added. The mixture wasdumped after 6 minutes. To the resulting mixture zinc oxide and ZBECwere added and further mixed on a two-roll mill operating at 30° C.

Curing

The t_(c)90, delta torques, were determined according to ASTM D-5289with the use of a Moving Die Rheometer (MDR 2000E) using a frequency ofoscillation of 1.7 Hz and a 1° arc at 160° C. for 30 minutes total runtime.

TABLE 29 Ex. MH ML MH-ML t_(s)1 t_(s)2 No. (dNm) (dNm) (dNm) (min) (min)t_(c)90 54 6.54 2.2 4.38 1.17 1.63 2.81 55 8.4 3.56 4.84 1 1.34 1.52 568.26 3.41 4.85 1.00 1.34 2.41

As evidenced by the examples the brominated elastomer according to theinvention shows a superior cure rate and cure state as compared to itsanalogue containing high levels of calcium stearate in pharmaceuticalclosure formulations. Very good results may be obtained even using areduced amount of curing agents.

When comparing examples 54 to 56 with respect to their modulus, hardnessand compression set it is apparent that with the brominated elastomeraccording to the invention even using lower amounts of curing agentsvery good physical properties are achieved. The low compression setrindicates improved crosslink density.

TABLE 30 Modulus Modulus Compression Ex. Temp. @ 100% @ 300% Hardnessset No. (° C.) (MPa) (MPa) Shore A (%) 43 160 0.89 1.19 48 62 44 1601.14 2.51 49 39 45 160 1.09 2.51 49 40

Stress strain dumbbells were cured at specified temperature (160° C.)for t_(c)90+5 and tested using the Alpha T2000 tensile tester. The ASTMD412 Method A procedure were followed to test samples that were unaged.

Hardness was determined according to ASTM D2240 A.

Compression set was measured according to ASTM D395 Method B.

What is claimed is:
 1. A slurry comprising: a dispersion of particles ofa halogenated elastomer in an aqueous medium; and at least one lowercritical solution temperature (LCST) compound having a cloud point of 0to 100° C.
 2. The slurry of claim 1, wherein the LCST compound ispresent in an amount of 1 to 5,000 ppm measured with respect to anamount of the halogenated elastomer.
 3. The slurry of claim 1, whereinthe slurry includes 1 to 2,000 ppm of antioxidant based on a totalweight of the aqueous medium.
 4. The slurry of claim 1, wherein thehalogenated elastomer comprise repeating units derived from at least oneisoolefin and repeating units derived from at least one multiolefin. 5.The slurry of claim 4, wherein the isoolefin includes an isoolefinhaving 4 to 16 carbon atoms, optionally wherein the isoolefin isisobutene.
 6. The slurry of claim 5, wherein the multiolefin includesisoprene, butadiene, 2-methylbutadiene, 2,4-dimethylbutadiene,piperyline, 3-methyl-1,3-pentadiene, 2,4-hexadiene,2-neopentylbutadiene, 2-methyl-1,5-hexadiene,2,5-dimethyl-2,4-hexadiene, 2-methyl-1,4-pentadiene,4-butyl-1,3-pentadiene, 2,3-dimethyl-1,3-pentadiene,2,3-dibutyl-1,3-pentadiene, 2-ethyl-1,3-pentadiene,2-ethyl-1,3-butadiene, 2-methyl-1,6-heptadiene, cyclopentadiene,methylcyclopentadiene, cyclohexadiene or 1-vinyl-cyclohexadiene.
 7. Theslurry of claim 1, wherein the halogenated elastomer comprises repeatingunits derived from isobutene and repeating units derived from isoprene.8. The slurry of claim 1, wherein the slurry comprises at least 20 ofthe particles per liter, wherein the particles have a particle size of0.05 to 25 mm.
 9. The slurry of claim 8, wherein the slurry comprises atleast 100 of the particles per liter, wherein the particles have aparticle size of 0.3 to 10 mm.
 10. The slurry of claim 9, wherein theLCST compound has a cloud point of 15 to 80° C.
 11. The slurry of claim10, wherein the slurry includes an organic diluent.
 12. A mixturecomprising: a dispersion of particles of a halogenated elastomer in anaqueous medium; at least one lower critical solution temperature (LCST)compound in the aqueous medium having a cloud point of 0 to 100° C.; andan organic diluent.
 13. The mixture of claim 12, wherein the halogenatedelastomer comprises repeating units derived from isobutene and repeatingunits derived from isoprene.
 14. The mixture of claim 13, wherein themixture has a temperature of 50° C. to 100° C.
 15. The mixture of claim14, wherein the LCST compound is present in an amount of 1 to 5,000 ppmmeasured with respect to the amount of the halogenated elastomer. 16.The mixture of claim 12, wherein the slurry includes 1 to 2,000 ppm ofantioxidant based on a total weight of the aqueous medium.
 17. Themixture of claim 13, wherein the LCST compound has a cloud point of 15to 80° C.
 18. The mixture of claim 17, wherein the organic diluentincludes one or more hydrocarbons selected from the group consisting ofpropane, isobutane, pentane, methycyclopentane, isohexane,2-methylpentane, 3-methylpentane, 2-methylbutane, 2,2-dimethylbutane,2,3-dimethylbutane, 2-methylhexane, 3-methylhexane, 3-ethylpentane,2,2-dimethylpentane, 2,3-dimethylpentane, 2,4-dimethylpentane,3,3-dimethyl pentane, 2-methylheptane, 3-ethylhexane,2,5-dimethylhexane, 2,2,4,-trimethylpentane, octane, heptane, butane,ethane, methane, nonane, decane, dodecane, undecane, hexane, methylcyclohexane, cyclopropane, cyclobutane, cyclopentane,methylcyclopentane, 1,1-dimethylcycopentane,cis-1,2-dimethylcyclopentane, trans-1,2-dimethylcyclopentane,trans-1,3-dimethyl-cyclopentane, ethylcyclopentane, cyclohexane, andmethylcyclohexane.
 19. The mixture of claim 18, wherein the organicdiluent includes the hydrocarbon and a hydrochlorocarbon.
 20. Themixture of claim 19, wherein the hydrochlorocarbon includesdichloromethane.